Possible FIN7 DGA Command and Control Behavioredit

This rule detects a known command and control pattern in network events. The FIN7 threat group is known to use this command and control technique, while maintaining persistence in their target’s network.

Rule type: query

Rule indices:

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

Severity: high

Risk score: 73

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
  • Network
  • Threat Detection
  • Command and Control
  • Host

Version: 6 (version history)

Added (Elastic Stack release): 7.10.0

Last modified (Elastic Stack release): 7.14.0

Rule authors: Elastic

Rule license: Elastic License v2

Potential false positivesedit

This rule could identify benign domains that are formatted similarly to FIN7’s command and control algorithm. Alerts should be investigated by an analyst to assess the validity of the individual observations.

Investigation guideedit

## Triage and analysis

In the event this rule identifies benign domains in your environment, the `destination.domain` field in the rule can be modified to include those domains. Example: `...AND NOT destination.domain:(zoom.us OR benign.domain1 OR benign.domain2)`.

Rule queryedit

event.category:(network OR network_traffic) AND type:(tls OR http) AND
network.transport:tcp AND
destination.domain:/[a-zA-Z]{4,5}\.(pw|us|club|info|site|top)/ AND NOT
destination.domain:zoom.us

Threat mappingedit

Framework: MITRE ATT&CKTM

Rule version historyedit

Version 6 (7.14.0 release)
  • Updated query, changed from:

    event.category:(network OR network_traffic) AND type:(tls OR http) AND
    network.transport:tcp AND
    destination.domain:/[a-zA-Z]{4,5}\.(pw|us|club|info|site|top)/ AND NOT
    destination.domain:zoom.us
Version 5 (7.13.0 release)
  • Formatting only
Version 4 (7.12.0 release)
  • Formatting only
Version 3 (7.11.2 release)
  • Formatting only
Version 2 (7.11.0 release)
  • Formatting only