DNS Tunneling

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Detects unusually large numbers of DNS queries for a single top-level DNS domain, which is often used for DNS tunneling. DNS tunneling can be used for command-and-control, persistence, or data exfiltration activity. For example, dnscat tends to generate many DNS questions for a top-level domain as it uses the DNS protocol to tunnel data.

Rule type: machine_learning

Machine learning job: packetbeat_dns_tunneling

Machine learning anomaly threshold: 50

Severity: low

Risk score: 21

Runs every: 15 minutes

Searches indices from: now-45m (Date Math format, see also Additional look-back time)

Maximum alerts per execution: 100

References:

Tags:

  • Elastic
  • Network
  • Threat Detection
  • ML

Version: 3 (version history)

Added (Elastic Stack release): 7.7.0

Last modified (Elastic Stack release): 7.10.0

Rule authors: Elastic

Rule license: Elastic License

Potential false positives

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DNS domains that use large numbers of child domains, such as software or content distribution networks, can trigger this alert and such parent domains can be excluded.

Rule version history

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Version 3 (7.10.0 release)
  • Formatting only
Version 2 (7.9.0 release)
  • Formatting only