Detection rules › Sigma
Suspicious Screensaver Binary File Creation
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
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Persistence | T1546.002 Event Triggered Execution: Screensaver |
| Privilege Escalation | T1546.002 Event Triggered Execution: Screensaver |
Event coverage
| Provider | Event | Title |
|---|---|---|
| Sysmon | Event ID 11 | FileCreate |
Rule body yaml
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
Stages and Predicates
Stage 0: condition
selection and not 1 of filter_*Stage 1: selection
selection:
TargetFilename|endswith: '.scr'
Stage 2: not filter_*
filter_generic:
Image|endswith:
- '\Kindle.exe'
- '\Bin\ccSvcHst.exe'
filter_tiworker:
Image|endswith: '\TiWorker.exe'
TargetFilename|endswith: '\uwfservicingscr.scr'
Exclusions
Top-level NOT(...) conjuncts: predicates this rule actively suppresses.
| Field | Kind | Excluded values |
|---|---|---|
Image | ends_with | \TiWorker.exe |
TargetFilename | ends_with | \uwfservicingscr.scr |
Image | ends_with | \Bin\ccSvcHst.exe |
Image | ends_with | \Kindle.exe |
Indicators
Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.
| Field | Kind | Values |
|---|---|---|
TargetFilename | ends_with |
|