huntrule

Windows Security: Detect Obfuscated PowerShell IEX Invocation via ServiceFileName Patterns (Event ID 4697)

Alerts on EventID 4697 instances where ServiceFileName matches obfuscated IEX-style PowerShell invocation patterns consistent with Invoke-Obfuscation.

FreeReviewedSigma · High · v2
Product
windows
Service
security
Author
Daniel Bohannon (@Mandiant/@FireEye), oscd.community (SigmaHQ), DRL 1.1
Published
2019-11-08
Updated
2026-07-31
AnalysisDetection

ATT&CK techniques

Defense Evasion

  1. Recon

  2. Resource Dev

  3. Initial Access

  4. Execution

  5. Persistence

  6. Priv Esc

  7. Defense Evasion

  8. Cred Access

  9. Discovery

  10. Lateral Movement

  11. Collection

  12. C2

  13. Exfiltration

  14. Impact

What it detects

This rule flags Windows Security audit Event ID 4697 where the recorded service binary path contains specific strings consistent with obfuscated PowerShell IEX invocation patterns. Attackers commonly use obfuscation to evade command-line inspection and to hide the real payload delivery mechanism. Telemetry relies on the Security log producing Event ID 4697 along with the ServiceFileName field matching multiple predefined regular-expression patterns.

Reporting behind it

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Suspicious Payload Staging in ProgramData IntelDriver Folder (via file_event)
Suspicious In-Memory Runspace Execution via PowerShell Script Block
Suspicious Python Inline Deobfuscation and Execution One-Liner
Suspicious PowerShell Reflective Assembly Load With Registry Property Read via Script Block (via ps_script)
Suspicious Archive Extraction From AppData Staging Folder via Process Creation
Suspicious Encoded PowerShell Using Base64 Stream Decompression Routines (via process_creation)
Windows Security: Detect Obfuscated PowerShell IEX Invocation via ServiceFileName Patterns (Event ID 4697)
Pivot detection · T1027 · 9 related

Changelog

v2
  1. v2
    Candidate ingested via manual entry.2026-07-31
  2. v1
    No changelog recorded for this version.2026-07-30

Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.