Armadillov25xv26x

Hunt Hypothesis

This YARA rule targets specific memory signatures associated with the Armadillo malware family, indicating the presence of a known threat actor’s implant within the environment. Proactively hunting for these signatures allows the SOC to identify dormant or low-noise infections that may have evaded traditional network-based detections, ensuring early containment before lateral movement or data exfiltration occurs.

YARA Rule

rule Armadillov25xv26x
{
      meta:
		author="malware-lu"
strings:
		$a0 = { 55 8B EC 6A FF 68 [4] 68 [4] 64 A1 00 00 00 00 50 64 89 25 00 00 00 00 83 EC 58 53 56 57 89 65 E8 FF 15 58 [3] 33 D2 8A D4 89 15 EC }

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

• Scenario: A DevOps engineer uses Terraform or Ansible to provision new virtual machines or containers, where the underlying hypervisor or container runtime (e.g., Hyper-V, Docker) loads specific kernel modules or driver binaries associated with Armadillo’s low-level system access capabilities.
  • Filter/Exclusion: Exclude processes where the parent process is terraform.exe, ansible-playbook.exe, or dockerd.exe, and the file path resides in standard infrastructure-as-code directories (e.g., C:\ProgramData\terraform\, /usr/local/bin/ansible/).
• Scenario: An IT administrator runs Windows Update or WSUS client services to install cumulative updates, which temporarily loads signed system drivers or updates that match the byte patterns of Armadillo’s user-mode components during the installation transaction.
  • Filter/Exclusion: Exclude files located in C:\Windows\WinSxS\ or C:\Windows\Installer\ that have a valid Microsoft Authenticode signature and are being accessed by TrustedInstaller.exe or wuauclt.exe.
• Scenario: A security team performs a memory dump analysis using tools like WinDbg or Volatility, where the tool loads memory-mapped images of previously captured system states that contain remnants of Armadillo’s injected code or driver structures from a prior incident.
  • Filter/Exclusion: Exclude processes where the parent is windbg.exe, volatility3.exe, or floss.exe, and the file extension is .dmp, .raw, or .mem.
• Scenario: A backup solution like Veeam or Commvault creates a snapshot or restores a virtual machine, causing the hypervisor to load guest OS drivers or restore system files that include Armadillo’s known