hatman injector

Hunt Hypothesis

This detection identifies adversary behavior where malicious processes inject code into legitimate system threads to evade standard execution monitoring and establish persistence. Proactively hunting for this pattern in Azure Sentinel is critical because it reveals stealthy injection techniques that may bypass initial signature-based alerts, allowing the SOC team to validate process integrity before lateral movement occurs.

YARA Rule

rule hatman_injector : hatman {
    condition:
        filesize < 100KB and hatman_injector_int and not hatman_payload_int
}

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
• Source Rule

False Positive Guidance

Here are 5 specific false positive scenarios for the hatman_injector detection rule in an enterprise environment, including suggested filters and exclusions:

• Antivirus Real-Time Scanning & Heuristics Engine Updates

  • Scenario: Enterprise Endpoint Detection and Response (EDR) solutions like CrowdStrike Falcon, SentinelOne, or Microsoft Defender for Endpoint frequently inject code into system processes to perform real-time scanning, memory integrity checks, or heuristic analysis. When these agents update their internal modules or scan a large batch of files, they often utilize CreateRemoteThread or similar injection techniques that mimic the behavior flagged by the YARA rule.
  • Filter/Exclusion: Exclude process paths belonging to known security vendors (e.g., C:\Program Files\CrowdStrike\, C:\Windows\System32\MsMpEng.exe) and filter out events where the parent process is a recognized EDR service running under the SYSTEM or Local Service account.

• Software Deployment via SCCM/Intune (Application Installation)

  • Scenario: During scheduled maintenance windows, tools like Microsoft Endpoint Configuration Manager (MECM/SCCM) or Microsoft Intune deploy software updates and patches. The deployment agents often inject DLLs into worker processes to manage installation states, apply hotfixes, or execute post-installation scripts. This is particularly common when installing complex enterprise suites like the Microsoft 365 Apps for Enterprise or Adobe Acrobat DC.
  • Filter/Exclusion: Create an exclusion based on the parent process name ccmexec.exe (SCCM) or IntuneManagementExtension.exe. Additionally, filter by specific command-line arguments containing keywords like /install, /update, or Microsoft.Intune.Management.

• Legacy Application Compatibility Layers

  • Scenario: