{"id":"c048f047-7e2a-4888-b302-55f509d4a91d","title":"SCR File Write Event","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.","author":"Christopher Peacock @securepeacock, SCYTHE @scythe_io","status":"test","level":"medium","date":"2022-04-27","modified":"2023-08-23","tags":["attack.stealth","attack.t1218.011"],"technique_ids":["T1218.011"],"logsource":{"category":"file_event","product":"windows"},"falsepositives":["The installation of new screen savers by third party software"],"references":["https://lolbas-project.github.io/lolbas/Libraries/Desk/"],"source_path":"rules/windows/file/file_event/file_event_win_new_scr_file.yml","source_sha256":"7dfcab08c65b02c473687bcc258ead05ae36f172f36e9037d888cebf27eeed93","source_url":"https://github.com/anpa1200/sigma/blob/b249e9683190cffdcaf188ccbfb90bf4759844e1/rules/windows/file/file_event/file_event_win_new_scr_file.yml","license":"Detection Rule License 1.1","license_url":"https://github.com/SigmaHQ/Detection-Rule-License/blob/main/LICENSE.Detection.Rules.md","yaml":"title: SCR File Write Event\nid: c048f047-7e2a-4888-b302-55f509d4a91d\nstatus: test\ndescription: 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.\nreferences:\n    - https://lolbas-project.github.io/lolbas/Libraries/Desk/\nauthor: 'Christopher Peacock @securepeacock, SCYTHE @scythe_io'\ndate: 2022-04-27\nmodified: 2023-08-23\ntags:\n    - attack.stealth\n    - attack.t1218.011\nlogsource:\n    category: file_event\n    product: windows\ndetection:\n    selection:\n        TargetFilename|endswith: '.scr'\n    filter:\n        TargetFilename|contains:\n            - ':\\$WINDOWS.~BT\\NewOS\\'\n            - ':\\Windows\\System32\\'\n            - ':\\Windows\\SysWOW64\\'\n            - ':\\Windows\\WinSxS\\'\n            - ':\\WUDownloadCache\\' # Windows Update Download Cache\n    condition: selection and not filter\nfalsepositives:\n    - The installation of new screen savers by third party software\nlevel: medium\n","validation":"yaml_parsed_not_backend_compiled_or_live_validated","techniques":[{"key":"enterprise/T1218.011","id":"T1218.011","name":"Rundll32","page":"techniques/enterprise/T1218.011/"}],"data_path":"data/detection-rules/c048f047-7e2a-4888-b302-55f509d4a91d.json","kind":"sigma"}