PseudoSigner01PEPack099Anorganix

Hunt Hypothesis

This detection identifies potentially malicious PE executables exhibiting characteristics of the Anorganix malware family through specific YARA signature matching. A proactive hunt is essential to uncover early-stage threats that may evade standard signature-based defenses and prevent lateral movement within the Azure Sentinel environment before escalation occurs.

YARA Rule

rule PseudoSigner01PEPack099Anorganix
{
      meta:
		author="malware-lu"
strings:
		$a0 = { 60 E8 11 00 00 00 5D 83 ED 06 80 BD E0 04 90 90 01 0F 84 F2 FF CC 0A E9 }

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

Here are 4 specific false positive scenarios for the PseudoSigner01PEPack099Anorganix detection rule, along with suggested filters and exclusions:

• Scenario: Automated Patch Deployment via SCCM/Intune

  • Context: During scheduled maintenance windows, System Center Configuration Manager (SCCM) or Microsoft Intune pushes cumulative updates to endpoints. The deployment agent often extracts PE binaries using a generic internal signing certificate that matches the “PseudoSigner” profile defined in the rule, triggering alerts for every deployed patch package.
  • Suggested Filter/Exclusion: Create an exclusion based on the Process Name (ccmsetup.exe or Microsoft.Update.Client.exe) and restrict the alert to non-business hours (e.g., 02:00–06:00 local time) where these scheduled jobs typically run.

• Scenario: Internal DevOps Artifact Signing

  • Context: The enterprise’s internal CI/CD pipeline (e.g., Jenkins or Azure DevOps) builds and signs custom .NET applications using a private “Anorganix” code signing certificate before distributing them to the file server. When these artifacts are copied to user workstations, the YARA rule flags the binary signature as suspicious due to the specific pseudo-signer attributes.
  • Suggested Filter/Exclusion: Implement a whitelist for the Issuer Name in the certificate metadata (e.g., CN=Internal-DevOps-Signing-Org) or exclude files located within the designated build artifact directory path (\\fileserver\builds\artifacts\).

• Scenario: Antivirus Quarantine and Scanning Operations

  • Context: The endpoint protection suite (e.g., CrowdStrike Falcon, SentinelOne, or Microsoft Defender) performs deep heuristic scans on downloaded executables. When the AV engine extracts