RODHighTECHAyman

Hunt Hypothesis

This detection identifies high-tech adversary activity characterized by specific file signatures defined in the RODHighTECHAyman YARA rule, which may indicate early-stage reconnaissance or lateral movement within the environment. Proactive hunting for this signal is essential to uncover low-severity indicators that could represent the initial foothold of a sophisticated threat actor before they escalate their operations.

YARA Rule

rule RODHighTECHAyman
{
      meta:
		author="malware-lu"
strings:
		$a0 = { 60 8B 15 1D 13 40 00 F7 E0 8D 82 83 19 00 00 E8 58 0C 00 00 }

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 4 specific false positive scenarios for the RODHighTECHAyman detection rule, including suggested filters and exclusions tailored for a legitimate enterprise environment:

• Antivirus Engine Updates via Windows Update Service

  • Scenario: The svchost.exe process (specifically the Wuauserv service) initiates an update cycle that triggers the YARA signature when downloading or unpacking new definition signatures. This is common in environments using Microsoft Defender for Endpoint or Symantec Endpoint Protection where updates occur during business hours.
  • Filter/Exclusion: Add a process exclusion for C:\Windows\System32\svchost.exe where the command line contains Wuauserv. Alternatively, exclude file paths matching C:\ProgramData\Microsoft\Windows Defender\* or C:\Program Files (x86)\Symantec\Symantec Endpoint Protection\*.

• Scheduled PowerShell Script Execution for IT Automation

  • Scenario: An automated nightly job runs a custom PowerShell script (IT_Maintenance.ps1) to audit user accounts or clean up temporary files. The script invokes powershell.exe which loads various .NET assemblies that match the YARA pattern, often triggered by Task Scheduler under the SYSTEM account.
  • Filter/Exclusion: Create an exclusion for C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe running with a command line argument containing -ExecutionPolicy Bypass -File "C:\Scripts\IT_Maintenance.ps1". Ensure the user context is restricted to specific service accounts (e.g., DOMAIN\svc-automation).

• Microsoft Office Add-in Installation or Update

  • Scenario: The Microsoft Office Click-to-Run installer (OfficeClickToRun.exe) updates a specific add-in (such as Adobe