DllUnregisterServer Function Call Via Msiexec.EXE

testmedium

log source: windows · process_creationauthor frack113date 2022-04-24

description

What this is, in brief.

Detects MsiExec loading a DLL and calling its DllUnregisterServer function

rule source (YAML)

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: 2026-10-19
tags:
    - attack.stealth
    - attack.t1218.007
logsource:
    product: windows
    category: process_creation
detection:
    selection_img:
        - Image|endswith: '\msiexec.exe'
        - OriginalFileName: '\msiexec.exe'
    selection_cli:
        CommandLine|contains|windash: ' -z '
        CommandLine|contains: '.dll'
    filter_optional_msihandler:
        CommandLine|endswith: '\MsiExec.exe" /Z "C:\Windows\CCM\MsiHandler.dll"'
    condition: all of selection_* and not 1 of filter_optional_*
falsepositives:
    - Unknown
level: medium
regression_tests_path: regression_data/rules/windows/process_creation/proc_creation_win_msiexec_dll/info.yml

detects techniques (1)

ATT&CK techniques this enables or maps to.

T1218.007Msiexec

references

External citations — patches, advisories, analysis.