Tamper Windows Defender Remove-MpPreference - ScriptBlockLogging — Sigma Rule

Rule metadata and linked tags

Author: Nasreddine Bencherchali (Nextron Systems). Source status: test; severity: high. Source dates: 2022-08-05 / not supplied.

{
  "product": "windows",
  "category": "ps_script",
  "definition": "Requirements: Script Block Logging must be enabled"
}

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: daa8de010f8a177b4e29735bdc9c5137809084c2b022041a290146dfcbe8d170

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: Tamper Windows Defender Remove-MpPreference - ScriptBlockLogging
id: ae2bdd58-0681-48ac-be7f-58ab4e593458
related:
    - id: 07e3cb2c-0608-410d-be4b-1511cb1a0448
      type: similar
status: test
description: Detects attempts to remove Windows Defender configuration using the 'MpPreference' cmdlet
references:
    - https://techcommunity.microsoft.com/t5/core-infrastructure-and-security/windows-10-controlled-folder-access-event-search/ba-p/2326088
author: Nasreddine Bencherchali (Nextron Systems)
date: 2022-08-05
tags:
    - attack.defense-impairment
    - attack.t1685
logsource:
    product: windows
    category: ps_script
    definition: 'Requirements: Script Block Logging must be enabled'
detection:
    selection_remove:
        ScriptBlockText|contains: 'Remove-MpPreference'
    selection_tamper:
        ScriptBlockText|contains:
            - '-ControlledFolderAccessProtectedFolders '
            - '-AttackSurfaceReductionRules_Ids '
            - '-AttackSurfaceReductionRules_Actions '
            - '-CheckForSignaturesBeforeRunningScan '
    condition: all of selection_*
falsepositives:
    - Legitimate PowerShell scripts
level: high

Original YAML and metadata in JSON

False positives

• Legitimate PowerShell scripts

Source references

• https://techcommunity.microsoft.com/t5/core-infrastructure-and-security/windows-10-controlled-folder-access-event-search/ba-p/2326088