Unusual Linux System Owner or User Discovery Activityedit

Looks for commands related to system user or owner discovery from an unusual user context. This can be due to uncommon troubleshooting activity or due to a compromised account. A compromised account may be used to engage in system owner or user discovery in order to identify currently active or primary users of a system. This may be a precursor to additional discovery, credential dumping or privilege elevation activity.

Rule type: machine_learning

Machine learning job: v3_linux_system_user_discovery

Machine learning anomaly threshold: 75

Severity: low

Risk score: 21

Runs every: 15 minutes

Searches indices from: now-45m (Date Math format, see also Additional look-back time)

Maximum alerts per execution: 100

Tags:

  • Elastic
  • Host
  • Linux
  • Threat Detection
  • ML

Version: 100 (version history)

Added (Elastic Stack release): 7.10.0

Last modified (Elastic Stack release): 8.5.0

Rule authors: Elastic

Rule license: Elastic License v2

Potential false positivesedit

Uncommon user command activity can be due to an engineer logging onto a server instance in order to perform manual troubleshooting or reconfiguration. ==== Threat mapping

Framework: MITRE ATT&CKTM

Rule version historyedit

Version 100 (8.5.0 release)
  • Formatting only
Version 3 (8.3.0 release)
  • Formatting only
Version 2 (7.12.0 release)
  • Formatting only