Winlogon Notify Key Logon Persistence

Hunt Hypothesis

Adversaries may abuse features of Winlogon to execute DLLs and/or executables when a user logs in. Winlogon.exe is a Windows component responsible for actions at logon/logoff as well as the secure att

Detection Rule

Sigma (Original)

title: Winlogon Notify Key Logon Persistence
id: bbf59793-6efb-4fa1-95ca-a7d288e52c88
status: test
description: |
    Adversaries may abuse features of Winlogon to execute DLLs and/or executables when a user logs in.
    Winlogon.exe is a Windows component responsible for actions at logon/logoff as well as the secure attention sequence (SAS) triggered by Ctrl-Alt-Delete.
references:
    - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1547.004/T1547.004.md#atomic-test-3---winlogon-notify-key-logon-persistence---powershell
author: frack113
date: 2021-12-30
modified: 2023-08-17
tags:
    - attack.privilege-escalation
    - attack.persistence
    - attack.t1547.004
logsource:
    category: registry_set
    product: windows
detection:
    selection:
        TargetObject|endswith: '\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\Notify\logon'
        Details|endswith: '.dll'
    condition: selection
falsepositives:
    - Unknown
level: high

KQL (Azure Sentinel)

imRegistry
| where RegistryKey endswith "\\SOFTWARE\\Microsoft\\Windows NT\\CurrentVersion\\Winlogon\\Notify\\logon" and RegistryValueData endswith ".dll"

KQL (Microsoft 365 Defender)

DeviceRegistryEvents
| where RegistryKey endswith "\\SOFTWARE\\Microsoft\\Windows NT\\CurrentVersion\\Winlogon\\Notify\\logon" and RegistryValueData endswith ".dll"

Required Data Sources

False Positive Guidance

• Unknown

MITRE ATT&CK Context

• Tactic: Privilege Escalation
• Tactic: Persistence
• Technique: T1547.004 — T1547.004

References

• https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1547.004/T1547.004.md#atomic-test-3---winlogon-notify-key-logon-persistence---powershell
• SigmaHQ Rule