Armadillov252b2

Hunt Hypothesis

This hunt detects potential adversary activity involving the execution of files matching the Armadillov252b2 signature, which may indicate early-stage reconnaissance or benign tool usage within the environment. A SOC team should proactively investigate these detections in Azure Sentinel to distinguish between legitimate administrative tasks and subtle indicators of compromise that could precede more severe security incidents.

YARA Rule

rule Armadillov252b2
{
      meta:
		author="malware-lu"
strings:
		$a0 = { 55 8B EC 6A FF 68 B0 [3] 68 60 [3] 64 A1 [4] 50 64 89 25 [4] 83 EC 58 53 56 57 89 65 E8 FF 15 24 }

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 3-5 specific false positive scenarios for the Armadillov252b2 detection rule in an enterprise environment, including suggested filters and exclusions:

• Endpoint Protection Scanner Scans

  • Scenario: The native YARA scanner within CrowdStrike Falcon or Microsoft Defender for Endpoint periodically scans the C:\Program Files\Armadillo directory. During these scheduled deep scans, the engine may re-execute the Armadillo binary and trigger the rule as a new detection event rather than a known benign process.
  • Filter/Exclusion: Exclude processes where the parent executable is falcon-sensor.exe (CrowdStrike) or MsMpEng.exe (Defender) when scanning files within the C:\Program Files\Armadillo path. Alternatively, add a whitelist for the specific SHA256 hash of the Armadillo binary in the EDR console.

• Scheduled Backup and Archiving Jobs

  • Scenario: Enterprise backup solutions like Veeam Backup & Replication or Rubrik run nightly jobs that compress and archive logs generated by the Armadillo application. The backup agent creates temporary instances of the Armadillo service to read data, which mimics the behavior pattern defined in the YARA rule (e.g., file creation or specific memory allocation).
  • Filter/Exclusion: Create a detection exclusion based on the process name Veeam.Backup.Service.exe or RubrikAgent.exe. Additionally, filter out alerts occurring during the configured maintenance window (e.g., 02:00 – 04:00 UTC) where these backup jobs are active.

• Software Deployment and Patching via SCCM/Intune

  • Scenario: During a scheduled patch cycle, **Microsoft Endpoint Configuration Manager