Detection of Snake Malware File Artifacts

The Snake malware (also known as Turla) is a highly sophisticated modular implant used for long-term espionage. A specific behavioral artifact associated with this malware is the creation of files with a .crmlog extension within the %windows%\Registration directory. These files typically follow a naming convention consisting of two random GUIDs separated by a dot (e.g., <RANDOM_GUID>.<RANDOM_GUID>.crmlog). The malware utilizes these files to support its operational capabilities, which include data exfiltration, system compromise, and covert communication. Defenders should monitor for file creation events within the specified path to identify potential instances of the Snake implant. Due to the nature of the Windows Registration folder, security teams should tune detections to account for potential benign activity by native system processes.

Impact

Successful deployment of the Snake malware leads to persistent unauthorized access to the compromised host. This allows attackers to perform comprehensive surveillance, exfiltrate sensitive data, and maintain long-term footholds within targeted networks, particularly in government, military, and research sectors.

Recommendation

• Deploy the provided Sigma rule to monitor for suspicious file creations within the Windows Registration directory.
• Establish baseline behavior for the %windows%\Registration folder to differentiate Snake artifacts from legitimate system service operations.
• Integrate Sysmon Event ID 11 (FileCreate) into SIEM telemetry to ensure visibility into file modifications in system-protected directories.
• Investigate any hosts flagging this activity by reviewing associated process parent-child relationships and file access permissions.