Armadillo500SiliconRealmsToolworks

Hunt Hypothesis

This hypothesis targets the presence of the Armadillo500SiliconRealmsToolworks YARA signature, indicating potential use of specific tooling or artifacts associated with this unique identifier. Proactively hunting for this signature allows the SOC team to identify low-severity indicators of compromise or staging activities that may precede more significant adversary actions within the Azure Sentinel environment.

YARA Rule

rule Armadillo500SiliconRealmsToolworks
{
      meta:
		author="malware-lu"
strings:
		$a0 = { E8 E3 40 00 00 E9 16 FE FF FF 6A 0C 68 [4] E8 44 15 00 00 8B 4D 08 33 FF 3B CF 76 2E 6A E0 58 33 D2 F7 F1 3B 45 0C 1B C0 40 75 1F E8 36 13 00 00 C7 00 0C 00 00 00 57 57 57 57 57 E8 C7 12 00 00 83 C4 14 33 C0 E9 D5 00 00 00 0F AF 4D 0C 8B F1 89 75 08 3B F7 75 03 33 F6 46 33 DB 89 5D E4 83 FE E0 77 69 83 3D [4] 03 75 4B 83 C6 0F 83 E6 F0 89 75 0C 8B 45 08 3B 05 [4] 77 37 6A 04 E8 48 11 00 00 59 89 7D FC FF 75 08 E8 01 49 00 00 59 89 45 E4 C7 45 FC FE FF FF FF E8 5F 00 00 00 8B 5D E4 3B DF 74 11 FF 75 08 57 53 E8 66 D3 FF FF 83 C4 0C 3B DF 75 61 56 6A 08 FF 35 [4] FF 15 [4] 8B D8 3B DF 75 4C 39 3D [4] 74 33 56 E8 AF F9 FF FF 59 85 C0 0F 85 72 FF FF FF 8B 45 10 3B C7 0F 84 50 FF FF FF C7 00 0C 00 00 00 E9 45 FF FF FF 33 FF 8B 75 0C 6A 04 E8 EE 0F 00 00 59 C3 }

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 developer or DevOps engineer runs the armadillo CLI tool (a hypothetical or niche internal tooling suite for silicon realm provisioning) to validate firmware signatures on a build server. The binary or its associated script library contains the specific string patterns or memory structures targeted by the YARA rule, causing a match during the file scan.

  • Filter/Exclusion: Exclude files located in the C:\Program Files\Armadillo500\bin\ directory or paths containing \toolworks\ from the YARA scan scope. Alternatively, add a hash-based exclusion for the known good SHA256 of the armadillo-cli.exe binary.

• Scenario: A scheduled maintenance job runs a custom PowerShell script named SiliconRealms_Maintenance.ps1 that invokes a helper DLL (Toolworks.dll) to perform disk defragmentation and log rotation on domain controllers. The YARA rule matches the specific byte sequence in the Toolworks.dll header or a hardcoded string used for logging purposes.

  • Filter/Exclusion: Create a process-based exclusion for powershell.exe when the command line arguments contain SiliconRealms_Maintenance and the parent process is svchost.exe (indicating a scheduled task). Additionally, exclude the specific path C:\Windows\System32\Tasks\SiliconRealms\ from file-based YARA scanning.

• Scenario: An enterprise endpoint detection agent (such as CrowdStrike Falcon or Microsoft Defender for Endpoint) performs a real-time memory scan on a Java application server running a custom module named RealmsToolworks.jar. The YARA rule is applied to the process memory and matches the class name or a specific constant string embedded in the bytecode.

  • Filter/Exclusion: Exclude process names java.exe or javaw.exe from memory-based