SEAAXE

Hunt Hypothesis

This detection identifies potential adversary activity involving specific file patterns or behaviors matched by the SEAAXE YARA signature within the Azure Sentinel environment. A proactive hunt is recommended to uncover early-stage threats that may not trigger high-severity alerts but could indicate a broader campaign requiring deeper investigation and context analysis.

YARA Rule

rule SEAAXE
{
      meta:
		author="malware-lu"
strings:
		$a0 = { FC BC [2] 0E 1F E8 [2] 26 A1 [2] 8B 1E [2] 2B C3 8E C0 B1 ?? D3 E3 }

condition:
		$a0 at pe.entry_point
}

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 1 string patterns in its detection logic.

• Source Rule

False Positive Guidance

False Positive Scenarios for Rule: SEAAXE

• Scenario 1: Scheduled Antivirus Definition Updates

  • Context: The enterprise’s endpoint protection suite (e.g., Microsoft Defender or CrowdStrike) performs automated signature database updates during off-hours. These update processes often spawn temporary child processes that match the behavioral patterns targeted by the SEAAXE YARA rule, specifically regarding file creation and registry modifications in secure directories.
  • Suggested Filter/Exclusion: Create an exclusion based on process lineage. Exclude alerts where the parent process is MsMpEng.exe (Microsoft Defender) or csagent.exe (CrowdStrike) executing within the standard update window (e.g., 02:00–04:00 UTC).

• Scenario 2: Automated Backup and Archiving Jobs

  • Context: Enterprise backup solutions like Veeam or Commvault run scheduled jobs that compress and archive large datasets. These tools frequently utilize temporary staging folders to stage data before transmission, triggering the SEAAXE rule due to high-volume file I/O and specific hash patterns associated with compressed archives (.zip/.7z).
  • Suggested Filter/Exclusion: Implement a path-based exclusion for known backup staging directories (e.g., C:\ProgramData\Veeam\Backup or D:\Commvault\Staging). Additionally, filter out alerts where the process name matches vbrsvc.exe or commvault_agent.exe.

• Scenario 3: Software Deployment via Configuration Management

  • Context: IT administrators use tools like Microsoft Endpoint Configuration Manager (SCCM) or Ansible to push software updates and patches. During deployment, these agents extract installation packages to temporary locations (C:\Windows\Temp), which often mimics the file extraction behavior detected by SEAAXE, leading to alerts on legitimate package unpacking