This documentation contains work-in-progress information for future Elastic Stack and Cloud releases. Use the version selector to view supported release docs. It also contains some Elastic Cloud serverless information. Check out our serverless docs for more details.

« System Information Discovery via Windows Command Shell System Shells via Services »

› › ›

System Log File Deletion

edit

System Log File Deletion

edit

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:

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: 101 (version history)

Added (Elastic Stack release): 7.11.0

Last modified (Elastic Stack release): 8.6.0

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",
"/var/log/boot.log", "/var/log/kern.log" ) and not
process.name : ("gzip")

Threat mapping

edit

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/

Rule version history

edit

Version 101 (8.6.0 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"
) and not process.name : ("gzip")

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

« System Information Discovery via Windows Command Shell System Shells via Services »