System Log File Deletion

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Identifies the deletion of sensitive Linux system logs. This may indicate an attempt to evade detection or destroy forensic evidence on a system.

Rule type: eql

Rule indices:

  • auditbeat-*
  • logs-endpoint.events.*

Severity: medium

Risk score: 47

Runs every: 5 minutes

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

Maximum alerts per execution: 100

References:

Tags:

  • Elastic
  • Host
  • Linux
  • Threat Detection
  • Defense Evasion

Version: 100 (version history)

Added (Elastic Stack release): 7.11.0

Last modified (Elastic Stack release): 8.5.0

Rule authors: Elastic

Rule license: Elastic License v2

Investigation guide

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Rule query

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file where event.type == "deletion" and file.path : (
"/var/run/utmp", "/var/log/wtmp", "/var/log/btmp",
"/var/log/lastlog", "/var/log/faillog", "/var/log/syslog",
"/var/log/messages", "/var/log/secure", "/var/log/auth.log"
) and not process.name : ("gzip")

Threat mapping

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Framework: MITRE ATT&CKTM

Rule version history

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Version 100 (8.5.0 release)
  • Formatting only
Version 6 (8.4.0 release)
  • Updated query, changed from:

    file where event.type == "deletion" and file.path : (
    "/var/run/utmp", "/var/log/wtmp", "/var/log/btmp",
    "/var/log/lastlog", "/var/log/faillog", "/var/log/syslog",
    "/var/log/messages", "/var/log/secure", "/var/log/auth.log"
    )
Version 4 (8.2.0 release)
  • Formatting only
Version 3 (7.12.0 release)
  • Formatting only
Version 2 (7.11.2 release)
  • Formatting only