Equation Group hack tool leaked by ShadowBrokers- file libXmexploit2.8

Hunt Hypothesis

The detection identifies potential exploitation of a leaked Equation Group tool, libXmexploit2.8, which could be used for unauthorized system access or data exfiltration. SOC teams should proactively hunt for this behavior in Azure Sentinel to identify and mitigate potential advanced persistent threats leveraging compromised tools.

YARA Rule

rule EquationGroup_libXmexploit2 {
   meta:
      description = "Equation Group hack tool leaked by ShadowBrokers- file libXmexploit2.8"
      author = "Florian Roth"
      reference = "https://medium.com/@shadowbrokerss/dont-forget-your-base-867d304a94b1"
      date = "2017-04-08"
      hash1 = "d7ed0234d074266cb37dd6a6a60119adb7d75cc6cc3b38654c8951b643944796"
   strings:
      $s1 = "Usage: ./exp command display_to_return_to" fullword ascii
      $s2 = "sizeof shellcode = %d" fullword ascii
      $s3 = "Execve failed!" fullword ascii
   condition:
      ( uint16(0) == 0x457f and filesize < 40KB and 1 of them )
}

Deployment Notes

This YARA rule can be deployed in the following contexts:

Microsoft Defender for Endpoint — Custom indicators / advanced hunting
Email Gateway — Attachment scanning
File Share Monitoring — Periodic scanning of shared drives
YARA CLI — Manual threat hunting on endpoints

This rule contains 3 string patterns in its detection logic.

References

False Positive Guidance

Scenario: Legitimate Use of libXmexploit2.8 in a Red Team Exercise
Description: A security team is conducting a red teaming exercise and is using the libXmexploit2.8 file as part of a simulated attack to test defenses.
Filter/Exclusion: Check for presence of red teaming tools or artifacts (e.g., metasploit, cobalt strike, or custom red team scripts) in the same process or timeline.
Scenario: Scheduled Job Using libXmexploit2.8 for System Maintenance
Description: A system maintenance job scheduled via cron or Task Scheduler is using libXmexploit2.8 to perform a legitimate system diagnostic or patching task.
Filter/Exclusion: Filter by process owner (e.g., root, system, or a known maintenance account) and check for scheduled job identifiers in the process tree.
Scenario: Admin Task Involving libXmexploit2.8 for Network Monitoring
Description: An administrator is using libXmexploit2.8 as part of a network monitoring tool to analyze traffic patterns or detect anomalies.
Filter/Exclusion: Filter by user context (e.g., admin, network, or security) and check for associated network monitoring tools (e.g., Wireshark, tcpdump, or Snort).
Scenario: File Integrity Monitoring Tool Using libXmexploit2.8
Description: A file integrity monitoring (FIM) tool is using libXmexploit2.8 as part of its analysis to detect unauthorized changes to system files.
Filter/Exclusion: Check for known FIM tools (e.g., OSSEC, Tripwire, or `Aqua Security