Suspicious Download Through Certutil.EXE (via process_creation)

title: Suspicious Download Through Certutil.EXE (via process_creation)
id: 1805a609-1a77-550d-9d6c-8d3ae6a3c9e9
status: stable
description: This rule detects the execution of certutil with certain flags that enable the utility to download files.
references:
    - https://attack.mitre.org/techniques/T1105/
    - https://attack.mitre.org/techniques/T1027/
    - https://learn.microsoft.com/en-us/windows-server/administration/windows-commands/certutil
    - https://forensicitguy.github.io/agenttesla-vba-certutil-download/
    - https://news.sophos.com/en-us/2021/04/13/compromised-exchange-server-hosting-cryptojacker-targeting-other-exchange-servers/
    - https://twitter.com/egre55/status/1087685529016193025
    - https://lolbas-project.github.io/lolbas/Binaries/Certutil/
    - https://www.hexacorn.com/blog/2020/08/23/certutil-one-more-gui-lolbin
author: Huntrule Team
date: 2026-07-11
tags:
    - attack.stealth
    - attack.t1027
    - attack.command-and-control
    - attack.t1105
logsource:
    category: process_creation
    product: windows
detection:
    selection_img:
        - Image|endswith: '\certutil.exe'
        - OriginalFileName: 'CertUtil.exe'
    selection_flags:
        CommandLine|contains:
            - 'urlcache '
            - 'verifyctl '
            - 'URL '
    selection_http:
        CommandLine|contains: 'http'
    filter_hr:
        CommandLine|contains: ctldl.windowsupdate.com
    condition: (all of selection_*) and not filter_hr
falsepositives:
    - Unknown
level: medium
regression_tests_path: regression_data/rules/windows/process_creation/proc_creation_win_certutil_download/info.yml