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
Malicious FIN7 Powertrash Loader Execution via Obfuscated PowerShell (via process_creation)
Suspicious XOR Obfuscated PowerShell from ClickFix Distribution
Suspicious PowerShell Executing Code from Environment Variable (via process_creation)
Suspicious In-Memory Runspace Execution via PowerShell Script Block
Suspicious Encoded PowerShell Using Base64 Stream Decompression Routines (via process_creation)
Suspicious PowerShell In-Memory Execution with AES Decryption
Suspicious Encoded PowerShell Command Execution
Suspicious PEAKLIGHT Memory-Only PowerShell Downloader Flags (via process_creation)
Obfuscated PowerShell Script: Indirect Cmdlet Execution via ExportedCommands Array Index
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.