Potential appverifUI.DLL Sideloading — Sigma Rule

Rule metadata and linked tags

Author: X__Junior (Nextron Systems). Source status: test; severity: high. Source dates: 2023-06-20 / not supplied.

{
  "category": "image_load",
  "product": "windows"
}

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: 42bf8b5c1bf69fe3b4ffb05ca238e70a9b461a257912bb65891f6e1ee79470c1

Detection logic

Original source YAML. Source-tag agreement is not proof of complete semantic coverage. This rule has not been compiled for a SIEM backend or validated against live telemetry here.

title: Potential appverifUI.DLL Sideloading
id: ee6cea48-c5b6-4304-a332-10fc6446f484
status: test
description: Detects potential DLL sideloading of "appverifUI.dll"
references:
    - https://web.archive.org/web/20220519091349/https://fatrodzianko.com/2020/02/15/dll-side-loading-appverif-exe/
author: X__Junior (Nextron Systems)
date: 2023-06-20
tags:
    - attack.persistence
    - attack.privilege-escalation
    - attack.execution
    - attack.stealth
    - attack.t1574.001
logsource:
    category: image_load
    product: windows
detection:
    selection:
        ImageLoaded|endswith: '\appverifUI.dll'
    filter_main_legit_path:
        Image:
            - 'C:\Windows\SysWOW64\appverif.exe'
            - 'C:\Windows\System32\appverif.exe'
        ImageLoaded|startswith:
            - 'C:\Windows\System32\'
            - 'C:\Windows\SysWOW64\'
            - 'C:\Windows\WinSxS\'
    condition: selection and not 1 of filter_main_*
falsepositives:
    - Unlikely
level: high

Original YAML and metadata in JSON

False positives

• Unlikely

Source references

• https://web.archive.org/web/20220519091349/https://fatrodzianko.com/2020/02/15/dll-side-loading-appverif-exe/