Sigma rule: Suspicious Uninstall of Windows Defender Feature via PowerShell

Rule

Title

Suspicious Uninstall of Windows Defender Feature via PowerShell

Status

experimental

Level

high

Author

yxinmiracle

Date

2025-08-22

File

rules/windows/process_creation/proc_creation_win_powershell_uninstall_defender_feature.yml

Commit

ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects the use of PowerShell with Uninstall-WindowsFeature or Remove-WindowsFeature cmdlets to disable or remove the Windows Defender GUI feature, a common technique used by adversaries to evade defenses.

Log source

product

windows

category

process_creation

Detection

selection_img:
    - Image|endswith:
          - '\powershell_ise.exe'
          - '\powershell.exe'
          - '\pwsh.exe'
    - OriginalFileName:
          - 'PowerShell_ISE.EXE'
          - 'PowerShell.EXE'
          - 'pwsh.dll'
selection_cli_uninstall:
    CommandLine|contains:
        - 'Uninstall-WindowsFeature'
        - 'Remove-WindowsFeature' # Only supported in Windows Server 2008 R2 and Windows 2012 R2
selection_cli_defender_feature:
    CommandLine|contains: 'Windows-Defender'
condition: all of selection_*

False positives (as the rule lists them)

• Unknown

Tags

• attack.defense-impairment
• attack.t1685

MITRE ATT&CK ids this rule names

• T1685

References

• https://learn.microsoft.com/en-us/powershell/module/microsoft.windows.servermanager.migration/uninstall-windowsfeature
• https://thedfirreport.com/2023/04/03/malicious-iso-file-leads-to-domain-wide-ransomware

Read on 2026-11-03T00:58:21.399Z under licence sigma-drl-1.1@d5f4c36a from https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules/windows/process_creation/proc_creation_win_powershell_uninstall_defender_feature.yml