Telnet Port Activityedit

This rule detects network events that may indicate the use of Telnet traffic. Telnet is commonly used by system administrators to remotely control older or embedded systems using the command line shell. It should almost never be directly exposed to the Internet, as it is frequently targeted and exploited by threat actors as an initial access or backdoor vector. As a plain-text protocol, it may also expose usernames and passwords to anyone capable of observing the traffic.

Rule type: query

Rule indices:

  • auditbeat-*
  • filebeat-*
  • packetbeat-*

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: None


  • Elastic
  • Host
  • Network
  • Threat Detection
  • Command and Control
  • Host

Version: 9

Rule authors:

  • Elastic

Rule license: Elastic License v2

Rule queryedit

event.category:(network or network_traffic) and network.transport:tcp and destination.port:23