Detection rules › Sigma
Potential appverifUI.DLL Sideloading
Detects potential DLL sideloading of "appverifUI.dll"
Known false positives
- Unlikely
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Execution | |
| Stealth |
Telemetry coverage
| Provider | Record / event type |
|---|---|
| Sysmon | Event ID 7: Image loaded |
Rule body
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
Stages and Predicates
Stage 0: condition
selection and not 1 of filter_main_*Stage 1: selection
selection:
ImageLoaded|endswith: '\appverifUI.dll'
Stage 2: not filter_main_legit_path
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\'
Exclusions
The rule actively suppresses these predicates.
| Field | Kind | Excluded values | Search |
|---|---|---|---|
Image | eq | C:\Windows\SysWOW64\appverif.exe | excludes:Image field:"Image" value:"C:\Windows\SysWOW64\appverif.exe" |
Image | eq | C:\Windows\System32\appverif.exe | excludes:Image field:"Image" value:"C:\Windows\System32\appverif.exe" |
ImageLoaded | starts_with | C:\Windows\SysWOW64\ | excludes:ImageLoaded field:"ImageLoaded" value:"C:\Windows\SysWOW64\" |
ImageLoaded | starts_with | C:\Windows\System32\ | excludes:ImageLoaded field:"ImageLoaded" value:"C:\Windows\System32\" |
ImageLoaded | starts_with | C:\Windows\WinSxS\ | excludes:ImageLoaded field:"ImageLoaded" value:"C:\Windows\WinSxS\" |
Indicators
These rows show field, operator, and value matches.
| Field | Kind | Values | Search |
|---|---|---|---|
ImageLoaded | ends_with |
| field:"ImageLoaded" kind:ends_with value:"\appverifUI.dll" |