huntrule

Windows PowerShell Command Lines Containing [char]0x or (WCHAR)0x Obfuscation Syntax

Identifies PowerShell execution command lines using suspicious [char]0x or (WCHAR)0x encoding patterns.

FreeReviewedSigma · High · v1
Product
windows
Category
process_creation
Author
Florian Roth (Nextron Systems) (SigmaHQ), DRL 1.1
Published
2020-07-09
Updated
2026-07-30
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 a PowerShell command line contains encoded character syntax patterns such as "[char]0x" or "(WCHAR)0x". Attackers commonly use these representations to obscure payload content and reduce readability for analysts and simple string-based detections. Detection relies on process creation telemetry and matching these specific substrings in the command line.

Reporting behind it

Related detections9 linkedT1027 — drag to rearrange
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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 PowerShell Command Lines Containing [char]0x or (WCHAR)0x Obfuscation Syntax
Pivot detection · T1027 · 9 related

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