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:

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:

Tags:

Version: 7

Rule authors:

Rule license: Elastic License v2

## Setup

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.

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")