Windows Defender Context Menu Removed
Detects the use of reg.exe or PowerShell to delete the Windows Defender context menu handler registry keys. This action removes the "Scan with Microsoft Defender" option from the right-click menu for files, directories, and drives. Attackers may use this technique to hinder manual, on-demand scans and reduce the visibility of the security product.
Convert In Phoenix Studio
Open this Sigma rule in the converter with the YAML preloaded and ready for backend selection.
Events generated when a new process is spawned on the system. Covers command-line arguments, parent/child relationships, and process metadata.
detection:
selection_img:
- Image|endswith:
- '\powershell_ise.exe'
- '\powershell.exe'
- '\pwsh.exe'
- '\reg.exe'
- OriginalFileName:
- 'powershell_ise.EXE'
- 'PowerShell.EXE'
- 'pwsh.dll'
- 'reg.exe'
selection_action:
CommandLine|contains:
- 'del'
- 'Remove-Item'
- 'ri '
selection_reg_path:
CommandLine|contains: '\shellex\ContextMenuHandlers\EPP'
condition: all of selection_*May be part of a system customization or "debloating" script, but this is highly unusual in a managed corporate environment.
Tactics
Sub-techniques