Malicious dnscat2 DNS Tunneling C2 Traffic

PremiumReviewedSigma · High · v1
Category
dns_query
Author
HuntRule
Published
2026-06-21
Updated
2026-08-28

ATT&CK techniques

C2 → Exfiltration
  1. Recon

  2. Resource Dev

  3. Initial Access

  4. Execution

  5. Persistence

  6. Priv Esc

  7. Defense Evasion

  8. Cred Access

  9. Discovery

  10. Lateral Movement

  11. Collection

  12. Impact

What it detects

This rule detects DNS queries containing the dnscat marker string used by the dnscat2 tunneling tool. It maps to command-and-control and data exfiltration over DNS where an operator encodes traffic in oversized MX and TXT lookups to evade network controls. Detecting the dnscat pattern surfaces DNS-based C2 beaconing.

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Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.