Suspicious Msiexec Execute Arbitrary DLL

Hunt Hypothesis

Adversaries may abuse msiexec.exe to proxy execution of malicious payloads. Msiexec.exe is the command-line utility for the Windows Installer and is thus commonly associated with executing installatio

Detection Rule

Sigma (Original)

title: Suspicious Msiexec Execute Arbitrary DLL
id: 6f4191bb-912b-48a8-9ce7-682769541e6d
status: test
description: |
    Adversaries may abuse msiexec.exe to proxy execution of malicious payloads.
    Msiexec.exe is the command-line utility for the Windows Installer and is thus commonly associated with executing installation packages (.msi)
references:
    - https://learn.microsoft.com/en-us/windows-server/administration/windows-commands/msiexec
    - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1218.007/T1218.007.md
    - https://twitter.com/_st0pp3r_/status/1583914515996897281
author: frack113
date: 2022-01-16
modified: 2026-01-09
tags:
    - attack.stealth
    - attack.t1218.007
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        Image|endswith: '\msiexec.exe'
        CommandLine|contains|windash: ' /Y'
    filter_main_legit_path:
        CommandLine|contains:
            - '\MsiExec.exe" /Y "C:\Program Files\'
            - '\MsiExec.exe" /Y "C:\Program Files (x86)\'
            - '\MsiExec.exe" /Y "C:\Windows\System32\'
            - '\MsiExec.exe" /Y "C:\Windows\SysWOW64\'
    condition: selection and not 1 of filter_main_*
falsepositives:
    - Legitimate script
level: medium

KQL (Azure Sentinel)

imProcessCreate
| where (TargetProcessName endswith "\\msiexec.exe" and (TargetProcessCommandLine contains " -Y" or TargetProcessCommandLine contains " /Y" or TargetProcessCommandLine contains " –Y" or TargetProcessCommandLine contains " —Y" or TargetProcessCommandLine contains " ―Y")) and (not((TargetProcessCommandLine contains "\\MsiExec.exe\" /Y \"C:\\Program Files\\" or TargetProcessCommandLine contains "\\MsiExec.exe\" /Y \"C:\\Program Files (x86)\\" or TargetProcessCommandLine contains "\\MsiExec.exe\" /Y \"C:\\Windows\\System32\\" or TargetProcessCommandLine contains "\\MsiExec.exe\" /Y \"C:\\Windows\\SysWOW64\\")))

Required Data Sources

False Positive Guidance

• Legitimate script

MITRE ATT&CK Context

• Technique: T1218.007 — T1218.007

References

• https://learn.microsoft.com/en-us/windows-server/administration/windows-commands/msiexec
• https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1218.007/T1218.007.md
• https://twitter.com/_st0pp3r_/status/1583914515996897281
• SigmaHQ Rule