Mknod Process Activity

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The Linux mknod program is sometimes used in the command payload of a remote command injection (RCI) and other exploits. It is used to export a command shell when the traditional version of netcat is not available to the payload.

Rule type: query

Rule indices:

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

Severity: low

Risk score: 21

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

Version: 6 (version history)

Added (Elastic Stack release): 7.6.0

Last modified (Elastic Stack release): 7.11.2

Rule authors: Elastic

Rule license: Elastic License

Potential false positives

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Mknod is a Linux system program. Some normal use of this program, at varying levels of frequency, may originate from scripts, automation tools, and frameworks. Usage by web servers is more likely to be suspicious.

Rule query

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event.category:process and event.type:(start or process_started) and
process.name:mknod

Rule version history

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Version 6 (7.11.2 release)
  • Formatting only
Version 5 (7.10.0 release)
  • Formatting only
Version 4 (7.9.1 release)
  • Formatting only
Version 3 (7.9.0 release)
  • Updated query, changed from:

    process.name:mknod and event.action:executed
Version 2 (7.7.0 release)
  • Updated query, changed from:

    process.name: mknod and event.action:executed