Potential Persistence Via Shim Database Modification

Hunt Hypothesis

Adversaries may establish persistence and/or elevate privileges by executing malicious content triggered by application shims. The Microsoft Windows Application Compatibility Infrastructure/Framework

Detection Rule

Sigma (Original)

title: Potential Persistence Via Shim Database Modification
id: dfb5b4e8-91d0-4291-b40a-e3b0d3942c45
status: test
description: |
    Adversaries may establish persistence and/or elevate privileges by executing malicious content triggered by application shims.
    The Microsoft Windows Application Compatibility Infrastructure/Framework (Application Shim) was created to allow for backward compatibility of software as the operating system codebase changes over time
references:
    - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1546.011/T1546.011.md#atomic-test-3---registry-key-creation-andor-modification-events-for-sdb
    - https://www.fireeye.com/blog/threat-research/2017/05/fin7-shim-databases-persistence.html
    - https://andreafortuna.org/2018/11/12/process-injection-and-persistence-using-application-shimming/
author: frack113
date: 2021-12-30
modified: 2025-10-22
tags:
    - attack.privilege-escalation
    - attack.persistence
    - attack.t1546.011
logsource:
    category: registry_set
    product: windows
detection:
    selection:
        TargetObject|contains:
            - '\SOFTWARE\Microsoft\Windows NT\CurrentVersion\AppCompatFlags\InstalledSDB\'
            - '\SOFTWARE\Microsoft\Windows NT\CurrentVersion\AppCompatFlags\Custom\'
    filter_main_empty_string:
        Details: ''
    filter_main_empty_value:
        Details: '(Empty)'
    filter_main_null:
        Details: null
    condition: selection and not 1 of filter_main_*
falsepositives:
    - Legitimate custom SHIM installations will also trigger this rule
level: medium

KQL (Azure Sentinel)

imRegistry
| where (RegistryKey endswith "\\SOFTWARE\\Microsoft\\Windows NT\\CurrentVersion\\AppCompatFlags\\InstalledSDB*" or RegistryKey endswith "\\SOFTWARE\\Microsoft\\Windows NT\\CurrentVersion\\AppCompatFlags\\Custom*") and (not((RegistryValueData =~ "" or RegistryValueData =~ "(Empty)" or isnull(RegistryValueData))))

KQL (Microsoft 365 Defender)

DeviceRegistryEvents
| where (RegistryKey endswith "\\SOFTWARE\\Microsoft\\Windows NT\\CurrentVersion\\AppCompatFlags\\InstalledSDB*" or RegistryKey endswith "\\SOFTWARE\\Microsoft\\Windows NT\\CurrentVersion\\AppCompatFlags\\Custom*") and (not((RegistryValueData =~ "" or RegistryValueData =~ "(Empty)" or isnull(RegistryValueData))))

Required Data Sources

False Positive Guidance

• Legitimate custom SHIM installations will also trigger this rule

MITRE ATT&CK Context

• Tactic: Privilege Escalation
• Tactic: Persistence
• Technique: T1546.011 — T1546.011

References

• https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1546.011/T1546.011.md#atomic-test-3---registry-key-creation-andor-modification-events-for-sdb
• https://www.fireeye.com/blog/threat-research/2017/05/fin7-shim-databases-persistence.html
• https://andreafortuna.org/2018/11/12/process-injection-and-persistence-using-application-shimming/
• SigmaHQ Rule