Hiding Files with Attrib.exe — Sigma Rule

Rule metadata and linked tags

Author: Sami Ruohonen. Source status: test; severity: medium. Source dates: 2019-01-16 / 2023-03-14.

{
  "category": "process_creation",
  "product": "windows"
}

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: 1880975d49992867918cc4fd72dfe3e71f09187e5ab85dc15bc7229b46cba34e

Detection logic

Original source YAML. Source-tag agreement is not proof of complete semantic coverage. This rule has not been compiled for a SIEM backend or validated against live telemetry here.

title: Hiding Files with Attrib.exe
id: 4281cb20-2994-4580-aa63-c8b86d019934
status: test
description: Detects usage of attrib.exe to hide files from users.
references:
    - https://unit42.paloaltonetworks.com/unit42-sure-ill-take-new-combojack-malware-alters-clipboards-steal-cryptocurrency/
    - https://www.uptycs.com/blog/lolbins-are-no-laughing-matter
author: Sami Ruohonen
date: 2019-01-16
modified: 2023-03-14
tags:
    - attack.stealth
    - attack.t1564.001
logsource:
    category: process_creation
    product: windows
detection:
    selection_img:
        - Image|endswith: '\attrib.exe'
        - OriginalFileName: 'ATTRIB.EXE'
    selection_cli:
        CommandLine|contains: ' +h '
    filter_main_msiexec:
        CommandLine|contains: '\desktop.ini '
    filter_optional_intel:
        ParentImage|endswith: '\cmd.exe'
        CommandLine: '+R +H +S +A \\\*.cui'
        ParentCommandLine: 'C:\\WINDOWS\\system32\\\*.bat'
    condition: all of selection_* and not 1 of filter_main_* and not 1 of filter_optional_*
falsepositives:
    - IgfxCUIService.exe hiding *.cui files via .bat script (attrib.exe a child of cmd.exe and igfxCUIService.exe is the parent of the cmd.exe)
    - Msiexec.exe hiding desktop.ini
level: medium

Original YAML and metadata in JSON

False positives

• IgfxCUIService.exe hiding *.cui files via .bat script (attrib.exe a child of cmd.exe and igfxCUIService.exe is the parent of the cmd.exe)
• Msiexec.exe hiding desktop.ini

Source references

• https://unit42.paloaltonetworks.com/unit42-sure-ill-take-new-combojack-malware-alters-clipboards-steal-cryptocurrency/
• https://www.uptycs.com/blog/lolbins-are-no-laughing-matter