NortonLifeLock Inc.
Employing SNI hostname extraction to populate a reverse DNS listing to protect against potentially malicious domains

Abstract:

Server Name Indication (SNI) hostname extraction to populate a reverse Domain Name System (DNS) listing to protect against potentially malicious domains. In some embodiments, a method may include detecting a Transport Layer Security (TLS) handshake between a first client application and a first server application, extracting an SNI hostname and an Internet Protocol (IP) address from the TLS handshake, populating the reverse DNS listing with the SNI hostname as a domain paired with the IP address, detecting communication between a second client application and the IP address, accessing the reverse DNS listing to determine the domain paired with the IP address, determining that the domain is a potentially malicious domain, and in response to determining that the domain is a potentially malicious domain, performing a remedial action to protect against the potentially malicious domain.