Vulnerable Driver Blocklist Registry Tampering Via CommandLine

Status: experimental
Severity: high
Log source: category process_creation, product windows
Author: Swachchhanda Shrawan Poudel (Nextron Systems)
Source: github.com/SigmaHQ/sigma

Detects tampering of the Vulnerable Driver Blocklist registry via command line tools such as PowerShell or REG.EXE. The Vulnerable Driver Blocklist is a security feature that helps prevent the loading of known vulnerable drivers. Disabling this feature may indicate an attempt to bypass security controls, often targeted by threat actors to facilitate the installation of malicious or vulnerable drivers, particularly in scenarios involving Endpoint Detection and Response

Known false positives

It is very unlikely for legitimate activities to disable the Vulnerable Driver Blocklist via command line tools; thus it is recommended to investigate promptly.

MITRE ATT&CK coverage

Tactic	Techniques
Defense Impairment	`T1685` Disable or Modify Tools

Telemetry coverage

Provider	Record / event type
Sysmon	Event ID 1: Process creation

Rule body

title: Vulnerable Driver Blocklist Registry Tampering Via CommandLine
id: 22154f0e-5132-4a54-aa78-cc62f6def531
related:
    - id: d526c60a-e236-4011-b165-831ffa52ab70
      type: similar
status: experimental
description: |
    Detects tampering of the Vulnerable Driver Blocklist registry via command line tools such as PowerShell or REG.EXE.
    The Vulnerable Driver Blocklist is a security feature that helps prevent the loading of known vulnerable drivers.
    Disabling this feature may indicate an attempt to bypass security controls, often targeted by threat actors
    to facilitate the installation of malicious or vulnerable drivers, particularly in scenarios involving Endpoint Detection and Response
references:
    - https://www.sophos.com/en-us/blog/sharpening-the-knife-gold-blades-strategic-evolution
    - https://learn.microsoft.com/en-us/windows/security/application-security/application-control/app-control-for-business/design/microsoft-recommended-driver-block-rules
author: Swachchhanda Shrawan Poudel (Nextron Systems)
date: 2026-01-26
tags:
    - attack.defense-impairment
    - attack.t1685
logsource:
    category: process_creation
    product: windows
detection:
    selection_img:
        - Image|endswith:
              - '\powershell.exe'
              - '\pwsh.exe'
              - '\reg.exe'
        - OriginalFileName:
              - 'PowerShell.EXE'
              - 'pwsh.dll'
              - 'reg.exe'
    selection_cli_1:
        CommandLine|contains:
            - 'add '
            - 'New-ItemProperty '
            - 'Set-ItemProperty '
            - 'si '  # SetItem Alias
    selection_cli_2:
        CommandLine|contains|all:
            - '\Control\CI\Config'
            - 'VulnerableDriverBlocklistEnable'
    condition: all of selection_*
falsepositives:
    - It is very unlikely for legitimate activities to disable the Vulnerable Driver Blocklist via command line tools; thus it is recommended to investigate promptly.
level: high
regression_tests_path: regression_data/rules/windows/process_creation/proc_creation_win_vulnerable_driver_blocklist_registry_tampering/info.yml

Stages and Predicates

Stage 0: `condition`

all of selection_*

Stage 1: `selection_img`

selection_img:
    - Image|endswith:
          - '\powershell.exe'
          - '\pwsh.exe'
          - '\reg.exe'
    - OriginalFileName:
          - 'PowerShell.EXE'
          - 'pwsh.dll'
          - 'reg.exe'

Stage 2: `selection_cli_1`

selection_cli_1:
    CommandLine|contains:
        - 'add '
        - 'New-ItemProperty '
        - 'Set-ItemProperty '
        - 'si '

Stage 3: `selection_cli_2`

selection_cli_2:
    CommandLine|contains|all:
        - '\Control\CI\Config'
        - 'VulnerableDriverBlocklistEnable'

Indicators

These rows show field, operator, and value matches.

Field	Kind	Values	Search
`CommandLine`	match	`New-ItemProperty` corpus 3 (sigma 3) `Set-ItemProperty` corpus 3 (sigma 3) `VulnerableDriverBlocklistEnable` `\Control\CI\Config` `add` corpus 12 (sigma 12) `si` corpus 5 (sigma 5)	`field:"CommandLine" kind:match`
`Image`	ends_with	`\powershell.exe` corpus 179 (sigma 178, kusto 1) `\pwsh.exe` corpus 165 (sigma 164, kusto 1) `\reg.exe` corpus 58 (sigma 58)	`field:"Image" kind:ends_with`
`OriginalFileName`	eq	`PowerShell.EXE` corpus 138 (sigma 84, splunk 30, elastic 24) `pwsh.dll` corpus 112 (sigma 79, splunk 30, elastic 3) `reg.exe` corpus 43 (sigma 32, splunk 8, elastic 3)	`field:"OriginalFileName" kind:eq`