huntrule

PowerShell command-line obfuscation indicators from special-character patterns (Windows)

Alerts on PowerShell executions whose command lines contain repeated special-character obfuscation patterns.

FreeReviewedSigma · High · v1
Product
windows
Category
process_creation
Author
Teymur Kheirkhabarov (idea), Vasiliy Burov (rule), oscd.community, Tim Shelton (fp) (SigmaHQ), DRL 1.1
Published
2020-10-15
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 creations where the executed binary is PowerShell (powershell.exe/pwsh.exe) and the command line contains repeated special-character patterns consistent with obfuscation. Attackers often use such formatting to hinder parsing and analysis while still running the same scripts. It relies on process creation telemetry, matching the command line against multiple regular-expression indicators and using image/path and optional allowlists to reduce known benign activity.

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
PowerShell command-line obfuscation indicators from special-character patterns (Windows)
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.