Suspicious New DLL Added to AppInit_DLLs Registry Key (via registry_event)

title: Suspicious New DLL Added to AppInit_DLLs Registry Key (via registry_event)
id: 693d3698-7f9b-56dc-acf9-e17d022ad81a
status: stable
description: This rule detects dLLs that are specified in the AppInit_DLLs value in the Registry key HKLM\Software\Microsoft\Windows NT\CurrentVersion\Windows are loaded by user32.dll into every process that loads user32.dll
references:
    - https://attack.mitre.org/techniques/T1546/010/
    - https://eqllib.readthedocs.io/en/latest/analytics/822dc4c5-b355-4df8-bd37-29c458997b8f.html
author: Huntrule Team
date: 2026-02-05
tags:
    - attack.privilege-escalation
    - attack.persistence
    - attack.t1546.010
logsource:
    category: registry_event
    product: windows
detection:
    selection:
        - TargetObject|endswith:
              - '\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Windows\AppInit_Dlls'
              - '\SOFTWARE\Wow6432Node\Microsoft\Windows NT\CurrentVersion\Windows\AppInit_Dlls'
        - NewName|endswith:
              - '\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Windows\AppInit_Dlls'
              - '\SOFTWARE\Wow6432Node\Microsoft\Windows NT\CurrentVersion\Windows\AppInit_Dlls'
    filter:
        Details: '(Empty)'
    condition: selection and not filter
falsepositives:
    - Unknown
level: medium