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Windows Defender Exclusion List Modified — Sigma Rule

Sigma rule 46a68649-f218-4f86-aea1-16a759d81820. Windows Defender Exclusion List Modified — Sigma Rule. Detects modifications to the Windows Defender exclusion registry key. This could indicate a potentially suspicious or even malicious activity by an attacker trying to add a new exclusion in order to bypass security.

Rule metadata and linked tags

Author: @BarryShooshooga. Source status: test; severity: medium. Source dates: 2019-10-26 / 2023-11-11.

{
  "product": "windows",
  "service": "security",
  "definition": "Requirements: Audit Policy : Security Settings/Local Policies/Audit Policy, Registry System Access Control (SACL): Auditing/User"
}

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: b70ab57b6760a522c25cbc7b0e92284e4c4845e46968d7063ab0d6e673f7d4b4

Detection logic

Original source YAML. Source-tag agreement is not proof of complete semantic coverage. This rule has not been compiled for a SIEM backend or validated against live telemetry here.

title: Windows Defender Exclusion List Modified
id: 46a68649-f218-4f86-aea1-16a759d81820
related:
    - id: e9c8808f-4cfb-4ba9-97d4-e5f3beaa244d
      type: derived
    - id: a33f8808-2812-4373-ae95-8cfb82134978
      type: derived
status: test
description: |
    Detects modifications to the Windows Defender exclusion registry key. This could indicate a potentially suspicious or even malicious activity by an attacker trying to add a new exclusion in order to bypass security.
references:
    - https://www.bleepingcomputer.com/news/security/gootkit-malware-bypasses-windows-defender-by-setting-path-exclusions/
author: '@BarryShooshooga'
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:
        EventID: 4657 # A registry value was modified.
        ObjectName|contains: '\Microsoft\Windows Defender\Exclusions\'
    condition: selection
falsepositives:
    - Intended exclusions by administrators
level: medium

Original YAML and metadata in JSON

False positives

  • Intended exclusions by administrators

Source references

Connected ecosystem references

Exact source-tagged techniques

Telemetry review

Read the original logsource above, then inspect the linked detection workspaces for technique-level sensor context. No per-rule telemetry equivalence is inferred.

Pinned research references. No browser attack runner, live simulation result or validated detector is asserted. Source mappings and validation limits are preserved. ATT&CK / Atomic provenance · Detection provenance.