Screensaver Plist File Modified by Unexpected Processedit

Identifies when a screensaver plist file is modified by an unexpected process. An adversary can maintain persistence on a macOS endpoint by creating a malicious screensaver (.saver) file and configuring the screensaver plist file to execute code each time the screensaver is activated.

Rule type: eql

Rule indices:

  • auditbeat-*

Severity: medium

Risk score: 47

Runs every: 5m

Searches indices from: now-9m (Date Math format, see also Additional look-back time)

Maximum alerts per execution: 100



  • Elastic
  • Host
  • macOS
  • Threat Detection
  • Persistence

Version: 2

Rule authors:

  • Elastic

Rule license: Elastic License v2

Investigation guideedit

## Triage and analysis

- Analyze the plist file modification event to identify whether the change was expected or not
- Investigate the process that modified the plist file for malicious code or other suspicious behavior
- Identify if any suspicious or known malicious screensaver (.saver) files were recently written to or modified on the host

## Config

If enabling an EQL rule on a non-elastic-agent index (such as beats) for versions <8.2, events will not define `event.ingested` and default fallback for EQL rules was not added until 8.2, so you will need to add a custom pipeline to populate `event.ingested` to @timestamp for this rule to work.

Rule queryedit

file where event.type != "deletion" and "*.plist" and
  file.path : (
    "/Library/Managed Preferences/*",
    ) and
  /* Filter OS processes modifying screensaver plist files */
  not process.executable : (