huntrule

Windows PowerShell Script Block Matching POWERTRASH Behavior Indicators

Detects PowerShell ScriptBlock text containing POWERTRASH-related in-memory and dynamic execution indicators on Windows.

FreeReviewedSigma · High · v5
Product
windows
Category
ps_script
Author
Nasreddine Bencherchali (Nextron Systems) (SigmaHQ), DRL 1.1
Published
2023-05-04
Updated
2026-07-31
AnalysisDetection

ATT&CK techniques

Execution

  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 PowerShell script content that includes a set of indicators commonly associated with dynamic in-memory execution patterns. Such behavior matters because attackers may embed and decode payloads (e.g., Base64), construct assemblies in memory, and invoke function pointers to run code without touching disk. The detection relies on telemetry that records PowerShell script block text and matches it against specific string components.

Reporting behind it

Related detections9 linkedT1059.001 — drag to rearrange
Suspicious Script Interpreter Spawned by Explorer via ClickFix Run Dialog (via process_creation)
Suspicious PowerShell Download Cradle via ClickFix Fake CAPTCHA (via process_creation)
Suspicious PowerShell EncodedCommand Spawned From Command Shell via Process Creation
Suspicious Script Download via Curl and PowerShell by Dohdoor
Malicious Mass Hyper-V Virtual Machine Shutdown via PowerShell by Kraken Ransomware
Suspicious PowerShell WebClient DownloadFile of Archive Payload (UAT-7237)
Suspicious SharePoint Worker Process Spawning Command Interpreter via ToolShell
Malicious Emmenhtal JavaScript Loader Spawning Encoded PowerShell
Suspicious Python Interpreter Launching Encoded PowerShell via subprocess
Windows PowerShell Script Block Matching POWERTRASH Behavior Indicators
Pivot detection · T1059.001 · 9 related

Changelog

v5
  1. v5
    Candidate ingested via manual entry.2026-07-31
  2. v4
    Candidate ingested via manual entry.2026-07-31
  3. v3
    Candidate ingested via manual entry.2026-07-31
  4. v2
    Candidate ingested via manual entry.2026-07-31
  5. 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.