Possible DNS Tunneling via Excessively Long Query Name

ATT&CK techniques

C2 → Exfiltration

Recon
Resource Dev
Initial Access
Execution
Persistence
Priv Esc
Defense Evasion
Cred Access
Discovery
Lateral Movement
Collection
C2
- T1071.004DNS
Exfiltration
- T1048Exfiltration Over Alternative Protocol
Impact

What it detects

This rule detects DNS queries with abnormally long names exceeding one hundred characters, a covert exfiltration signal described by Elastic for detecting DNS tunneling. Attackers encode stolen data into the subdomain labels of DNS requests to smuggle it past network controls over an allowed protocol. Sustained long query names to a single domain are a strong indicator of tunneling and merit investigation.

Reporting behind it

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Possible DNS Tunneling via Excessively Long Query Name

Pivot detection · T1071.004 · 9 related

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

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