Windows Security Audit: Registry Handle Write Access Requested for Defender Exclusions

Alerts on registry access requests with write/append permissions to Windows Defender exclusions key paths.

FreeReviewedSigma · Medium · v2

Product: windows
Service: security
Author: @BarryShooshooga, Nasreddine Bencherchali (Nextron Systems) (SigmaHQ), DRL 1.1
Published: 2019-10-26
Updated: 2026-07-31

ATT&CK techniques

Recon
Resource Dev
Initial Access
Execution
Persistence
Priv Esc
Defense Evasion
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule identifies Windows Security audit events where a process requests a handle and attempts access to the Windows Defender exclusions registry path. It matches handle request and access attempt events combined with registry object names under \Microsoft\Windows Defender\Exclusions\ and write-related access masks (WriteData and AppendData). Such activity can be used to modify Defender exclusion settings, weakening endpoint security. The detection relies on Security event telemetry for 4656 and 4663, including the requested access masks and the registry object name.

Reporting behind it

Related detections9 linkedT1685 — drag to rearrange

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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 Security Audit: Registry Handle Write Access Requested for Defender Exclusions

Pivot detection · T1685 · 9 related

Changelog

v2
Candidate ingested via manual entry.2026-07-31
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.

windows-security-event-handle-write-access-requested-on-defender-exclusions-regi-e9c8808f

title: "Windows Security Audit: Registry Handle Write Access Requested for Defender Exclusions"
id: 5b3c7933-64ee-4923-93ee-d3cbfd9e243c
related:
  - id: 46a68649-f218-4f86-aea1-16a759d81820
    type: derived
  - id: a33f8808-2812-4373-ae95-8cfb82134978
    type: derived
  - id: e9c8808f-4cfb-4ba9-97d4-e5f3beaa244d
    type: derived
status: test
description: This rule identifies Windows Security audit events where a process requests a handle and attempts access to the Windows Defender exclusions registry path. It matches handle request and access attempt events combined with registry object names under \Microsoft\Windows Defender\Exclusions\ and write-related access masks (WriteData and AppendData). Such activity can be used to modify Defender exclusion settings, weakening endpoint security. The detection relies on Security event telemetry for 4656 and 4663, including the requested access masks and the registry object name.
references:
  - https://www.bleepingcomputer.com/news/security/gootkit-malware-bypasses-windows-defender-by-setting-path-exclusions/
  - https://github.com/SigmaHQ/sigma/blob/master/rules/windows/builtin/security/win_security_windows_defender_exclusions_write_access.yml
author: "@BarryShooshooga, Nasreddine Bencherchali (Nextron Systems), Huntrule Team"
date: 2019-10-26
modified: 2023-11-11
tags:
  - attack.defense-impairment
  - attack.t1685
logsource:
  product: windows
  service: security
  definition: "Requirements: Audit Policy : Security Settings/Local Policies/Audit Policy, Registry System Access Control (SACL): Auditing/User"
detection:
  selection:
    AccessList|contains:
      - "%%4417"
      - "%%4418"
    EventID:
      - 4656
      - 4663
    ObjectName|contains: \Microsoft\Windows Defender\Exclusions\
  condition: selection
falsepositives:
  - Unknown
level: medium
license: DRL-1.1

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