Detection rules › Sigma
DllUnregisterServer Function Call Via Msiexec.EXE
Detects MsiExec loading a DLL and calling its DllUnregisterServer function
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Stealth |
Telemetry coverage
| Provider | Record / event type |
|---|---|
| Sysmon | Event ID 1: Process creation |
Rule body
title: DllUnregisterServer Function Call Via Msiexec.EXE
id: 84f52741-8834-4a8c-a413-2eb2269aa6c8
status: test
description: Detects MsiExec loading a DLL and calling its DllUnregisterServer function
references:
- https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1218.007/T1218.007.md
- https://lolbas-project.github.io/lolbas/Binaries/Msiexec/
- https://twitter.com/_st0pp3r_/status/1583914515996897281
author: frack113
date: 2022-04-24
modified: 2024-03-13
tags:
- attack.stealth
- attack.t1218.007
logsource:
product: windows
category: process_creation
detection:
selection_img:
- Image|endswith: '\msiexec.exe'
- OriginalFileName: '\msiexec.exe'
selection_flag:
CommandLine|contains|windash: ' -z '
selection_dll:
CommandLine|contains: '.dll'
condition: all of selection_*
falsepositives:
- Unknown
level: medium
Stages and Predicates
Stage 0: condition
all of selection_*Stage 1: selection_img
selection_img:
- Image|endswith: '\msiexec.exe'
- OriginalFileName: '\msiexec.exe'
Stage 2: selection_flag
selection_flag:
CommandLine|contains|windash: ' -z '
Stage 3: selection_dll
selection_dll:
CommandLine|contains: '.dll'
Indicators
These rows show field, operator, and value matches.
| Field | Kind | Values | Search |
|---|---|---|---|
CommandLine | match |
| field:"CommandLine" kind:match |
Image | ends_with |
| field:"Image" kind:ends_with value:"\msiexec.exe" |
OriginalFileName | eq |
| field:"OriginalFileName" kind:eq value:"\msiexec.exe" |