Armadillo440SiliconRealmsToolworks

Hunt Hypothesis

This rule identifies the presence of the Armadillo440SiliconRealmsToolworks tool, which adversaries may deploy to establish a foothold or execute specific tradecraft within the environment. Proactively hunting for this indicator allows the SOC team to detect low-severity tooling that could serve as a precursor to more significant lateral movement or data exfiltration activities in Azure Sentinel.

YARA Rule

rule Armadillo440SiliconRealmsToolworks
{
      meta:
		author="malware-lu"
strings:
		$a0 = { 31 2E 31 2E 34 00 00 00 C2 E0 94 BE 93 FC DE C6 B6 24 83 F7 D2 A4 92 77 40 27 CF EB D8 6F 50 B4 B5 29 24 FA 45 08 04 52 D5 1B D2 8C 8A 1E 6E FF 8C 5F 42 89 F1 83 B1 27 C5 69 57 FC 55 0A DD 44 BE 2A 02 97 6B 65 15 AA 31 E9 28 7D 49 1B DF B5 5D 08 A8 BA A8 }

condition:
		$a0
}

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 the armadillo CLI tool (a common open-source utility for ARM architecture cross-compilation or specific silicon validation tasks) on a build server to verify binary compatibility for new IoT firmware releases.
  • Filter/Exclusion: Exclude processes where the parent process is msbuild.exe or dotnet.exe and the working directory contains /build/ or /ci/ in the path.
• Scenario: An IT administrator runs the SiliconRealms diagnostic suite (a proprietary internal tool for validating CPU microcode updates) via a scheduled PowerShell task on domain controllers to ensure hardware integrity after patch Tuesday updates.
  • Filter/Exclusion: Exclude executions where the command line contains microcode or validate and the user account belongs to the Domain Admins or IT_Ops security group.
• Scenario: A QA engineer uses the Toolworks test harness (an internal framework for stress-testing application performance) in a development VM to simulate high-load scenarios before a major release.
  • Filter/Exclusion: Exclude processes running on hosts tagged with Environment=Dev or Environment=QA in the CMDB, or where the process path resides in C:\QA\Toolworks\.
• Scenario: A security analyst performs a manual threat hunt using the Armadillo memory scanning tool to inspect live process memory for signs of fileless malware on a suspected endpoint.
  • Filter/Exclusion: Exclude executions where the user account is in the SOC_Team group and the tool is launched from the C:\Tools\ThreatHunt\ directory.
• Scenario: A database administrator uses the SiliconRealms index optimization utility to reorganize table indexes on a SQL Server instance during a low-