huntrule

PowerShell Adds Windows Defender Exclusions via Add-MpPreference/Set-MpPreference

Flags PowerShell commands that add Windows Defender exclusions using Add-MpPreference/Set-MpPreference with exclusion parameters.

FreeReviewedSigma · Medium · v2
Product
windows
Category
ps_script
Author
Tim Rauch, Elastic (idea) (SigmaHQ), DRL 1.1
Published
2022-09-16
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 identifies PowerShell activity that adds or updates Windows Defender exclusion settings by matching script content containing Add-MpPreference or Set-MpPreference along with exclusion parameters (path, extension, process, or IP address). Attackers often use Defender exclusions to reduce visibility and hinder detection of subsequent malicious activity. It relies on PowerShell script block text telemetry (e.g., script block logging) to match the relevant command and exclusion arguments.

Reporting behind it

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Malicious AutoHotKey Runner AutoNotify Executing AHKBot Looper Script (via process_creation)
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PowerShell Adds Windows Defender Exclusions via Add-MpPreference/Set-MpPreference
Pivot detection · T1059 · 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.