Suspicious Long Alphanumeric DNS Subdomain Indicative of DNS Tunneling

ATT&CK techniques

C2

Recon
Resource Dev
Initial Access
Execution
Persistence
Priv Esc
Defense Evasion
Cred Access
Discovery
Lateral Movement
Collection
C2
- T1071.004DNS
- T1132.001Standard Encoding
Exfiltration
Impact

What it detects

This rule detects DNS queries whose leftmost label is an unusually long fixed-width alphanumeric string, matching the 28 to 31 character encoded subdomains used by the Saitama DNS implant to smuggle command-and-control data. Such high-entropy labels are a hallmark of DNS tunneling and warrant review of the querying host for a covert C2 channel.

Reporting behind it

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Suspicious Long Alphanumeric DNS Subdomain Indicative of DNS Tunneling

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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