huntrule

Windows Registry: Windows Defender Exclusions Key Modified via ObjectName Match

Alerts on registry value changes under the Windows Defender Exclusions key in Windows Security event 4657.

FreeReviewedSigma · Medium · v2
Product
windows
Service
security
Author
@BarryShooshooga (SigmaHQ), DRL 1.1
Published
2019-10-26
Updated
2026-07-31
AnalysisDetection

ATT&CK techniques

  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 Security event 4657 where a registry value modification targets a path under \Microsoft\Windows Defender\Exclusions\, indicating changes to Windows Defender’s configured exclusions. Attackers may use exclusions to reduce scanning and hinder detection of malicious files or locations. It relies on Windows Security auditing for registry value modifications (EventID 4657) and the presence of the Defender exclusions registry path in the event’s ObjectName field.

Reporting behind it

Related detections9 linkedT1685 — drag to rearrange
Suspicious Windows Defender Exclusion via Add-MpPreference (via process_creation)
Malicious Windows Defender Service Tampering via PowerShell (via process_creation)
Windows Defender Disabled via DisableAntiSpyware Registry Key
Suspicious Vulnerable Intel Ethernet Driver Load for BYOVD via SCATTERED SPIDER (via driver_load)
Malicious Defender Disable And Executable Exclusion Via Registry
Malicious UAC Disable via EnableLUA Registry Modification (via registry_set)
Malicious AMSI and ETW Patching via PowerShell Script
Malicious PowMix AMSI Bypass via amsiInitFailed
Suspicious ThrottleStop Driver Abuse for Defense Evasion in Ransomware Attacks
Windows Registry: Windows Defender Exclusions Key Modified via ObjectName Match
Pivot detection · T1685 · 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.