sigmaDRL-1.1from SigmaHQ/sigma

SCR File Write Event

Detects the creation of screensaver files (.scr) outside of system folders. Attackers may execute an application as an ".SCR" file using "rundll32.exe desk.cpl,InstallScreenSaver" for example.

Quality

100

FP risk

—

Forks

Views

ATT&CK techniques

T1218.011

Rule sourcerules/windows/file/file_event/file_event_win_new_scr_file.yml

title: SCR File Write Event
id: c048f047-7e2a-4888-b302-55f509d4a91d
status: test
description: Detects the creation of screensaver files (.scr) outside of system folders. Attackers may execute an application as an ".SCR" file using "rundll32.exe desk.cpl,InstallScreenSaver" for example.
references:
    - https://lolbas-project.github.io/lolbas/Libraries/Desk/
author: 'Christopher Peacock @securepeacock, SCYTHE @scythe_io'
date: 2022-04-27
modified: 2023-08-23
tags:
    - attack.defense-evasion
    - attack.t1218.011
logsource:
    category: file_event
    product: windows
detection:
    selection:
        TargetFilename|endswith: '.scr'
    filter:
        TargetFilename|contains:
            - ':\$WINDOWS.~BT\NewOS\'
            - ':\Windows\System32\'
            - ':\Windows\SysWOW64\'
            - ':\Windows\WinSxS\'
            - ':\WUDownloadCache\' # Windows Update Download Cache
    condition: selection and not filter
falsepositives:
    - The installation of new screen savers by third party software
level: medium