Armadillov182

Hunt Hypothesis

This detection identifies potential malware activity associated with the Armadillo family by leveraging a specific YARA signature to match known malicious patterns within endpoint telemetry. Proactive hunting for this indicator in Azure Sentinel is essential to uncover early-stage infections that may evade traditional signature-based defenses, allowing the SOC team to isolate affected assets before lateral movement occurs.

YARA Rule

rule Armadillov182
{
      meta:
		author="malware-lu"
strings:
		$a0 = { 55 8B EC 6A FF 68 E0 C1 40 00 68 74 81 40 00 64 A1 00 00 00 00 50 64 89 25 00 00 00 00 83 EC 58 }

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 5 specific false positive scenarios for the Armadillov182 detection rule, tailored for a legitimate enterprise environment:

• Scenario: The Microsoft Office 365 ProPlus Click-to-Run update service (OfficeClickToRun.exe) executes a background task to verify installation integrity or download patches. This process often spawns child processes that match the behavioral signature of Armadillov182, particularly when scanning the Program Files\Microsoft Office directory.

  • Filter/Exclusion: Add an exclusion for the executable path C:\Program Files\Microsoft Office\root\OfficeXX\OfficeClickToRun.exe and its child processes within the YARA rule or SIEM logic.

• Scenario: The enterprise utilizes CrowdStrike Falcon (or similar EDR) which runs a scheduled “On-Demand Scan” job every morning at 02:00 AM. During this scan, the agent’s scanning engine (C:\Program Files\CrowdStrike\FalconSensor\csfalcon.exe) generates file system artifacts and memory signatures that mimic the specific heuristic patterns defined in Armadillov182.

  • Filter/Exclusion: Create a time-based exclusion window (01:30 AM – 04:00 AM) for alerts triggered by csfalcon.exe or configure the YARA rule to ignore matches originating from the C:\Program Files\CrowdStrike\* directory tree.

• Scenario: An automated System Center Configuration Manager (SCCM/MECM) deployment pushes a new application package to endpoints. The SCCM client service (ccmexec.exe) extracts compressed payloads and executes installer scripts, which often trigger the specific file creation and process injection behaviors monitored by Armadillov182.

  • Filter/Exclusion: Exclude processes where the