huntrule

Windows Process Creation: Detect Obfuscated PowerShell IEX Invocation from Invoke-Obfuscation

Detects PowerShell commands showing obfuscation markers consistent with Invoke-Obfuscation-powered IEX invocation.

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

ATT&CK techniques

Execution → 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 process creation events where the PowerShell command line contains multiple string/variable patterns consistent with obfuscated IEX-style invocation generated by the Invoke-Obfuscation framework. Obfuscated invocation helps attackers reduce readability, evade basic detections, and execute code with less attention to intent. Detection relies on CommandLine telemetry captured at process start, matching several regular expressions tied to specific obfuscation artifacts.

Reporting behind it

Related detections9 linkedT1027 — drag to rearrange
Suspicious PowerShell Invoke-Expression with Replace Obfuscation
Malicious Emmenhtal JavaScript Loader Spawning Encoded PowerShell
Suspicious Python Interpreter Launching Encoded PowerShell via subprocess
Suspicious PS1Bot PowerShell Payload Written to ProgramData (via file_event)
Malicious Non-Interactive Encoded PowerShell Stager (via process_creation)
Suspicious Hidden PowerShell Executing Substring of Dropped File
PowerShell Encoded or Download-Cradle Command Line (via process_creation)
Obfuscated Encoded PowerShell Payload Deployed - PowerShell (via powershell)
Suspicious PowerShell AES Decryption and Reflective Method Invocation in SolarMarker
Windows Process Creation: Detect Obfuscated PowerShell IEX Invocation from Invoke-Obfuscation
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.