huntrule

Windows PowerShell: Detect Set-Alias/New-Alias Usage in Script Block Logging

Alerts on PowerShell scripts that create aliases via Set-Alias/New-Alias, a common obfuscation technique, using ScriptBlockText logging.

FreeReviewedSigma · Low · v4
Product
windows
Category
ps_script
Author
frack113 (SigmaHQ), DRL 1.1
Published
2023-01-08
Updated
2026-09-24
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 PowerShell script content that contains Set-Alias or New-Alias, which attackers can use to obscure command intent by creating alternate command names. It relies on Script Block Logging telemetry, matching on ScriptBlockText strings to identify alias creation activity and excluding specific known benign alias mappings. The detection is intended to surface potentially stealthy PowerShell execution patterns.

Reporting behind it

Related detections9 linkedT1027 — drag to rearrange
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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 PowerShell: Detect Set-Alias/New-Alias Usage in Script Block Logging
Pivot detection · T1027 · 9 related

Changelog

v4
  1. v4
    Candidate ingested via manual entry.2026-09-24
  2. v2
    Candidate ingested via manual entry.2026-07-31
  3. 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.