Suspicious File Download Through InstallUtil.EXE (via process_creation)

title: Suspicious File Download Through InstallUtil.EXE (via process_creation)
id: 3ded24c0-4249-53dd-83d7-6eb3f2020b05
status: stable
description: This rule detects use of .NET InstallUtil.exe to download arbitrary files. The files will be written to "%LOCALAPPDATA%\Microsoft\Windows\INetCache\IE\"
references:
    - https://attack.mitre.org/techniques/T1218/
    - https://github.com/LOLBAS-Project/LOLBAS/pull/239
author: Huntrule Team
date: 2026-03-18
tags:
    - attack.stealth
    - attack.t1218
logsource:
    category: process_creation
    product: windows
detection:
    selection_img:
        - Image|endswith: '\InstallUtil.exe'
        - OriginalFileName: 'InstallUtil.exe'
    selection_cli:
        CommandLine|contains:
            - 'ftp://'
            - 'http://'
            - 'https://'
    condition: all of selection_*
falsepositives:
    - Unknown
level: medium