DebuggerPattern SEH Inits

Hunt Hypothesis

The DebuggerPattern SEH Inits rule detects potential use of structured exception handling (SEH) initialization patterns that may indicate debugger interaction or code injection attempts. SOC teams should proactively hunt for this behavior in Azure Sentinel to identify early signs of adversarial activity that could lead to persistence or evasion techniques.

YARA Rule

rule DebuggerPattern__SEH_Inits : AntiDebug DebuggerPattern {
	meta:
		weight = 1
		Author = "naxonez"
		reference = "https://github.com/naxonez/yaraRules/blob/master/AntiDebugging.yara"
	strings:
		$ = {64 89 25 00 00 00 00}
	condition:
		any of them
}

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

References

• https://github.com/naxonez/yaraRules/blob/master/AntiDebugging.yara
• Source Rule

False Positive Guidance

• Scenario: Legitimate Use of Process Explorer for Debugging
  Description: A system administrator is using Process Explorer (Sysinternals tool) to investigate a process for performance tuning or troubleshooting.
  Filter/Exclusion: Exclude processes associated with Process Explorer (e.g., procexp.exe) or check for the presence of Sysinternals tool signatures in the process name or parent process.

• Scenario: Scheduled Job Performing Memory Analysis
  Description: A scheduled task runs a memory analysis tool (e.g., VMMap or Process Hacker) to monitor memory usage and detect leaks.
  Filter/Exclusion: Exclude processes launched by scheduled tasks with known names (e.g., Task Scheduler or schtasks.exe) or filter based on the command line arguments indicating memory analysis.

• Scenario: Admin Task Using Debug Diagnostic Tools (DebugDiag)
  Description: An administrator is using Debug Diagnostic Tools (DebugDiag) to analyze crash dumps or performance issues.
  Filter/Exclusion: Exclude processes launched by DebugDiag (e.g., DebugDiag.exe) or filter based on the presence of known DebugDiag command-line switches or parent process.

• Scenario: Antivirus or EDR Tool Performing Behavior Monitoring
  Description: An endpoint protection tool (e.g., CrowdStrike, SentinelOne) is using behavioral monitoring techniques that may resemble debugger activity.
  Filter/Exclusion: Exclude processes associated with known EDR/AV tools (e.g., CrowdStrike, SentinelOne, Bitdefender) or check for the presence of EDR tool signatures in the process tree.

• Scenario: Development Environment Using Visual Studio Debugger
  Description: A developer is debugging an application using Visual Studio, which may trigger debugger-related patterns in memory or process behavior.
  **Filter/