sigmamediumHunting

AddinUtil.EXE Execution From Uncommon Directory

Detects execution of the Add-In deployment cache updating utility (AddInutil.exe) from a non-standard directory.

MITRE ATT&CK

defense-evasion

Detection Query

selection:
  - Image|endswith: \addinutil.exe
  - OriginalFileName: AddInUtil.exe
filter_main_legit_location:
  Image|contains:
    - :\Windows\Microsoft.NET\Framework\
    - :\Windows\Microsoft.NET\Framework64\
    - :\Windows\Microsoft.NET\FrameworkArm\
    - :\Windows\Microsoft.NET\FrameworkArm64\
    - :\Windows\WinSxS\
condition: selection and not 1 of filter_main_*

Author

Michael McKinley (@McKinleyMike), Tony Latteri (@TheLatteri)

Created

2023-09-18

Data Sources

windowsProcess Creation Events

Platforms

windows

References

https://www.blue-prints.blog/content/blog/posts/lolbin/addinutil-lolbas.html

Tags

attack.defense-evasionattack.t1218

Raw Content

title: AddinUtil.EXE Execution From Uncommon Directory
id: 6120ac2a-a34b-42c0-a9bd-1fb9f459f348
status: test
description: Detects execution of the Add-In deployment cache updating utility (AddInutil.exe) from a non-standard directory.
references:
    - https://www.blue-prints.blog/content/blog/posts/lolbin/addinutil-lolbas.html
author: Michael McKinley (@McKinleyMike), Tony Latteri (@TheLatteri)
date: 2023-09-18
modified: 2025-02-24
tags:
    - attack.defense-evasion
    - attack.t1218
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        - Image|endswith: '\addinutil.exe'
        - OriginalFileName: 'AddInUtil.exe'
    filter_main_legit_location:
        Image|contains:
            - ':\Windows\Microsoft.NET\Framework\'
            - ':\Windows\Microsoft.NET\Framework64\'
            - ':\Windows\Microsoft.NET\FrameworkArm\'
            - ':\Windows\Microsoft.NET\FrameworkArm64\'
            - ':\Windows\WinSxS\'
    condition: selection and not 1 of filter_main_*
falsepositives:
    - Unknown
level: medium