- Tactics
- Command and Control
- Platforms
- Linux, macOS, Windows, ESXi
- Reference
- attack.mitre.org/techniques/T1568.001
Description
Adversaries may use Fast Flux DNS to hide a command and control channel behind an array of rapidly changing IP addresses linked to a single domain resolution. This technique uses a fully qualified domain name, with multiple IP addresses assigned to it which are swapped with high frequency, using a combination of round robin IP addressing and short Time-To-Live (TTL) for a DNS resource record.(Citation: MehtaFastFluxPt1)(Citation: MehtaFastFluxPt2)(Citation: Fast Flux - Welivesecurity)
The simplest, “single-flux” method, involves registering and de-registering an addresses as part of the DNS A (address) record list for a single DNS name. These registrations have a five-minute average lifespan, resulting in a constant shuffle of IP address resolution.(Citation: Fast Flux - Welivesecurity)
In contrast, the “double-flux” method registers and de-registers an address as part of the DNS Name Server record list for the DNS zone, providing additional resilience for the connection. With double-flux additional hosts can act as a proxy to the C2 host, further insulating the true source of the C2 channel.
How GTK Cyber trains on this
GTK Cyber's Threat Hunting with Data Science course teaches you to build machine-learning detections for techniques like this across the MITRE ATT&CK framework, including the Command and Control tactic this technique falls under. Practitioner-led, focused on real detections, not memorizing technique IDs.
Related techniques
- T1001 — Data Obfuscation
- T1008 — Fallback Channels
- T1071 — Application Layer Protocol
- T1090 — Proxy
- T1092 — Communication Through Removable Media
- T1095 — Non-Application Layer Protocol
- T1102 — Web Service
- T1104 — Multi-Stage Channels
- T1105 — Ingress Tool Transfer
- T1132 — Data Encoding
- T1205 — Traffic Signaling
- T1219 — Remote Access Tools