WebServer Access Logs Deleted

Elastic Stack Serverless Security

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

Rule type: eql

Rule indices:

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

Severity: medium

Risk score: 47

Runs every: 5m

Searches indices from: now-9m (https://www.elastic.co/guide/en/elasticsearch/reference/current/common-options.html#date-math[Date Math format], see also Additional look-back time)

Maximum alerts per execution: 100

References: None

Tags:

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

Version: 4

Rule authors:

• Elastic

Rule license: Elastic License v2

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 : ("C:\\inetpub\\logs\\LogFiles\\*.log",
               "/var/log/apache*/access.log",
               "/etc/httpd/logs/access_log",
               "/var/log/httpd/access_log",
               "/var/www/*/logs/access.log")

Framework: MITRE ATT&CKTM

• 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/