Potential Shell via Web Server

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Identifies suspicious commands executed via a web server, which may suggest a vulnerability and remote shell access.

Rule type: query

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
  • Persistence

Version: 11 (version history)

Added (Elastic Stack release): 7.6.0

Last modified (Elastic Stack release): 8.4.0

Rule authors: Elastic

Rule license: Elastic License v2

Potential false positives

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Network monitoring or management products may have a web server component that runs shell commands as part of normal behavior.

Rule query

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event.category:process and event.type:(start or process_started) and
process.name:(bash or dash or ash or zsh or "python*" or "perl*" or
"php*") and process.parent.name:("apache" or "nginx" or "www" or
"apache2" or "httpd" or "www-data")

Threat mapping

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Framework: MITRE ATT&CKTM

Rule version history

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Version 11 (8.4.0 release)
  • Updated query, changed from:

    event.category:process and event.type:(start or process_started) and
    process.name:(bash or dash) and user.name:(apache or nginx or www or
    "www-data")
Version 9 (7.12.0 release)
  • Formatting only
Version 8 (7.11.2 release)
  • Formatting only
Version 7 (7.11.0 release)
  • Formatting only
Version 6 (7.10.0 release)
  • Formatting only
Version 5 (7.9.1 release)
  • Formatting only
Version 4 (7.9.0 release)
  • Updated query, changed from:

    process.name:(bash or dash) and user.name:(apache or nginx or www or
    "www-data") and event.action:executed
Version 3 (7.8.0 release)
  • Updated query, changed from:

    process.name:bash and user.name:(apache or www or www-data) and
    event.action:executed
Version 2 (7.6.1 release)
  • Updated query, changed from:

    process.name: bash and user.name: (apache or www or "wwww-data") and
    event.action:executed