Suspicious Screensaver Binary File Creation — Sigma Rule

Rule metadata and linked tags

Author: frack113. Source status: test; severity: medium. Source dates: 2021-12-29 / 2022-11-08.

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

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: 8903c7caf51ca04527d174a43b949063dab2a915698c535582ac90519106e21a

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: Suspicious Screensaver Binary File Creation
id: 97aa2e88-555c-450d-85a6-229bcd87efb8
status: test
description: |
    Adversaries may establish persistence by executing malicious content triggered by user inactivity.
    Screensavers are programs that execute after a configurable time of user inactivity and consist of Portable Executable (PE) files with a .scr file extension
references:
    - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1546.002/T1546.002.md
author: frack113
date: 2021-12-29
modified: 2022-11-08
tags:
    - attack.privilege-escalation
    - attack.persistence
    - attack.t1546.002
logsource:
    product: windows
    category: file_event
detection:
    selection:
        TargetFilename|endswith: '.scr'
    filter_generic:
        Image|endswith:
            - '\Kindle.exe'
            - '\Bin\ccSvcHst.exe' # Symantec Endpoint Protection
    filter_tiworker:
        # ParentCommandLine: C:\WINDOWS\system32\svchost.exe -k DcomLaunch -p
        Image|endswith: '\TiWorker.exe'
        TargetFilename|endswith: '\uwfservicingscr.scr'
    condition: selection and not 1 of filter_*
falsepositives:
    - Unknown
level: medium

Original YAML and metadata in JSON

False positives

• Unknown

Source references

• https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1546.002/T1546.002.md