Screen Capture with Import Tool — Sigma Rule

Rule metadata and linked tags

Author: Pawel Mazur. Source status: test; severity: low. Source dates: 2021-09-21 / 2022-10-09.

{
  "product": "linux",
  "service": "auditd"
}

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: 83f91d59ded0078c90bcfcf01dcc1886c94360274b6a430c6ea8e342ea3578b6

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: Screen Capture with Import Tool
id: dbe4b9c5-c254-4258-9688-d6af0b7967fd
status: test
description: |
  Detects adversary creating screen capture of a desktop with Import Tool.
  Highly recommended using rule on servers, due to high usage of screenshot utilities on user workstations.
  ImageMagick must be installed.
references:
    - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1113/T1113.md
    - https://linux.die.net/man/1/import
    - https://imagemagick.org/
author: 'Pawel Mazur'
date: 2021-09-21
modified: 2022-10-09
tags:
    - attack.collection
    - attack.t1113
logsource:
    product: linux
    service: auditd
detection:
    import:
        type: EXECVE
        a0: import
    import_window_root:
        a1: '-window'
        a2: 'root'
        a3|endswith:
            - '.png'
            - '.jpg'
            - '.jpeg'
    import_no_window_root:
        a1|endswith:
            - '.png'
            - '.jpg'
            - '.jpeg'
    condition: import and (import_window_root or import_no_window_root)
falsepositives:
    - Legitimate use of screenshot utility
level: low

Original YAML and metadata in JSON

False positives

• Legitimate use of screenshot utility

Source references

• https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1113/T1113.md
• https://linux.die.net/man/1/import
• https://imagemagick.org/