TA0011 · COMMAND AND CONTROL
Domain Fronting
Adversaries may take advantage of routing schemes in Content Delivery Networks (CDNs) and other services which host multiple domains to obfuscate the intended destination of HTTPS traffic or traffic tunneled through HTTPS.
Detect it with
If SSL inspection is in place or the traffic is not encrypted, the Host field of the HTTP header can be checked if it matches the HTTPS SNI or against a blocklist or allowlist of domain names.
Why it matters on shift
Domain Fronting is one of the concrete ways adversaries achieve command and control. Recognising it in telemetry lets you name the technique in your ticket and pivot to what came before and after.
What to look for next
After command and control, the next tactic is usually Exfiltration. Search your telemetry for the transition before closing the ticket.
Kill-chain context