Windows File Creation: Custom Application Shim Database Files Created

Flags creation of custom Application Shim database files in AppPatch custom directories on Windows.

FreeReviewedSigma · Medium · v2
Product
windows
Category
file_event
Author
frack113, Nasreddine Bencherchali (Nextron Systems) (SigmaHQ), DRL 1.1
Published
2021-12-29
Updated
2026-07-31
title: "Windows File Creation: Custom Application Shim Database Files Created"
id: c78a8c0d-ca2d-407e-add9-97cc6b76cd6c
status: test
description: This rule flags the creation of custom Windows Application Compatibility Framework (Application Shim) database files in the default shim database directories. Attackers may use shim-based execution to persist and/or elevate privileges by triggering malicious content via application shimming. Detection relies on Windows file creation telemetry identifying newly created files whose paths contain the specified Custom and CustomSDB directories.
references:
  - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1546.011/T1546.011.md#atomic-test-2---new-shim-database-files-created-in-the-default-shim-database-directory
  - https://www.mandiant.com/resources/blog/fin7-shim-databases-persistence
  - https://liberty-shell.com/sec/2020/02/25/shim-persistence/
  - https://andreafortuna.org/2018/11/12/process-injection-and-persistence-using-application-shimming/
  - https://github.com/SigmaHQ/sigma/blob/master/rules/windows/file/file_event/file_event_win_creation_new_shim_database.yml
author: frack113, Nasreddine Bencherchali (Nextron Systems), Huntrule Team
date: 2021-12-29
modified: 2023-12-06
tags:
  - attack.privilege-escalation
  - attack.persistence
  - attack.t1547.009
logsource:
  product: windows
  category: file_event
detection:
  selection:
    TargetFilename|contains:
      - :\Windows\apppatch\Custom\
      - :\Windows\apppatch\CustomSDB\
  condition: selection
falsepositives:
  - Legitimate custom SHIM installations will also trigger this rule
level: medium
regression_tests_path: regression_data/rules/windows/file/file_event/file_event_win_creation_new_shim_database/info.yml
license: DRL-1.1
related:
  - id: ee63c85c-6d51-4d12-ad09-04e25877a947
    type: derived