System Log File Deletion

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: 5m

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

Maximum alerts per execution: 100

References:

https://www.fireeye.com/blog/threat-research/2020/11/live-off-the-land-an-overview-of-unc1945.html

Tags:

Elastic
Host
Linux
Threat Detection
Defense Evasion

Version: 6

Rule authors:

Elastic

Rule license: Elastic License v2

Investigation guide

edit

Rule query

edit

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")

Framework: MITRE ATT&CK^TM

Tactic:
- Name: Defense Evasion
- ID: TA0005
- Reference URL: https://attack.mitre.org/tactics/TA0005/
Technique:
- Name: Indicator Removal on Host
- ID: T1070
- Reference URL: https://attack.mitre.org/techniques/T1070/

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