Windows Registry: AppCertDlls NewName/TargetObject Creation for DLL Load Persistence

Alerts on Windows registry changes involving AppCertDlls paths that can enable malicious DLL loading for persistence.

FreeReviewedSigma · Medium · v1
Product
windows
Category
registry_event
Author
Ilyas Ochkov, oscd.community (SigmaHQ), DRL 1.1
Published
2019-10-25
Updated
2026-07-30
title: "Windows Registry: AppCertDlls NewName/TargetObject Creation for DLL Load Persistence"
id: 5c8a3b75-e405-4905-b589-f09d852d3a28
status: test
description: This rule flags registry events where the AppCertDlls value for the Session Manager location is created or modified via a detected TargetObject or NewName path. Attackers can abuse AppCertDlls to force a malicious DLL to be loaded into separate processes, supporting persistence and potential privilege escalation. Telemetry is based on Windows registry event logs capturing TargetObject and NewName for the AppCertDlls registry path.
references:
  - http://www.hexacorn.com/blog/2013/01/19/beyond-good-ol-run-key-part-3/
  - https://eqllib.readthedocs.io/en/latest/analytics/14f90406-10a0-4d36-a672-31cabe149f2f.html
  - https://github.com/SigmaHQ/sigma/blob/master/rules/windows/registry/registry_event/registry_event_new_dll_added_to_appcertdlls_registry_key.yml
author: Ilyas Ochkov, oscd.community, Huntrule Team
date: 2019-10-25
modified: 2021-11-27
tags:
  - attack.privilege-escalation
  - attack.persistence
  - attack.t1546.009
logsource:
  category: registry_event
  product: windows
detection:
  selection:
    - TargetObject: HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\AppCertDlls
    - NewName: HKLM\SYSTEM\CurentControlSet\Control\Session Manager\AppCertDlls
  condition: selection
falsepositives:
  - Unknown
level: medium
license: DRL-1.1
related:
  - id: 6aa1d992-5925-4e9f-a49b-845e51d1de01
    type: derived