Suspicious Driver Install by pnputil.exe

Hunt Hypothesis

Detects when a possible suspicious driver is being installed via pnputil.exe lolbin

Detection Rule

Sigma (Original)

title: Suspicious Driver Install by pnputil.exe
id: a2ea3ae7-d3d0-40a0-a55c-25a45c87cac1
status: test
description: Detects when a possible suspicious driver is being installed via pnputil.exe lolbin
references:
    - https://learn.microsoft.com/en-us/windows-hardware/drivers/devtest/pnputil-command-syntax
    - https://strontic.github.io/xcyclopedia/library/pnputil.exe-60EDC5E6BDBAEE441F2E3AEACD0340D2.html
author: Hai Vaknin @LuxNoBulIshit, Avihay eldad  @aloneliassaf, Austin Songer @austinsonger
date: 2021-09-30
modified: 2022-10-09
tags:
    - attack.privilege-escalation
    - attack.persistence
    - attack.t1547
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        CommandLine|contains:
            - '-i'
            - '/install'
            - '-a'
            - '/add-driver'
            - '.inf'
        Image|endswith: '\pnputil.exe'
    condition: selection
falsepositives:
    - Pnputil.exe being used may be performed by a system administrator.
    - Verify whether the user identity, user agent, and/or hostname should be making changes in your environment.
    - Pnputil.exe being executed from unfamiliar users should be investigated. If known behavior is causing false positives, it can be exempted from the rule.
level: medium

KQL (Azure Sentinel)

imProcessCreate
| where (TargetProcessCommandLine contains "-i" or TargetProcessCommandLine contains "/install" or TargetProcessCommandLine contains "-a" or TargetProcessCommandLine contains "/add-driver" or TargetProcessCommandLine contains ".inf") and TargetProcessName endswith "\\pnputil.exe"

Required Data Sources

False Positive Guidance

• Pnputil.exe being used may be performed by a system administrator.
• Verify whether the user identity, user agent, and/or hostname should be making changes in your environment.
• Pnputil.exe being executed from unfamiliar users should be investigated. If known behavior is causing false positives, it can be exempted from the rule.

MITRE ATT&CK Context

• Tactic: Privilege Escalation
• Tactic: Persistence
• Technique: T1547 — T1547

References

• https://learn.microsoft.com/en-us/windows-hardware/drivers/devtest/pnputil-command-syntax
• https://strontic.github.io/xcyclopedia/library/pnputil.exe-60EDC5E6BDBAEE441F2E3AEACD0340D2.html
• SigmaHQ Rule