Sub-technique of T1090 Proxy.View on attack.mitre.org
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. Domain fronting involves using different domain names in the SNI field of the TLS header and the Host field of the HTTP header. If both domains are served from the same CDN, then the CDN may route to the address specified in the HTTP header after unwrapping the TLS header. A variation of the the technique, "domainless" fronting, utilizes a SNI field that is left blank; this may allow the fronting to work even when the CDN attempts to validate that the SNI and HTTP Host fields match (if the blank SNI fields are ignored).
For example, if domain-x and domain-y are customers of the same CDN, it is possible to place domain-x in the TLS header and domain-y in the HTTP header. Traffic will appear to be going to domain-x, however the CDN may route it to domain-y.
Rules on DetectionCode tagged with T1090.004.
None recorded.
| Used by | Procedure example |
|---|---|
| GroupAPT29 | APT29 has used the meek domain fronting plugin for Tor to hide the destination of C2 traffic. |
| Used by | Procedure example |
|---|---|
| MalwareCobalt Strike | Cobalt Strike has the ability to accept a value for HTTP Host Header to enable domain fronting. |
| Toolmeek | meek uses Domain Fronting to disguise the destination of network traffic as another server that is hosted in the same Content Delivery Network (CDN) as the intended destination. |
| ToolMythic | Mythic supports domain fronting via custom request headers. |
| MalwareSMOKEDHAM | SMOKEDHAM has used a fronted domain to obfuscate its hard-coded C2 server domain. |
Data from MITRE ATT&CK® (Enterprise). ATT&CK® is a registered trademark of The MITRE Corporation.
