Radware Ltd.
Techniques for defense against domain name system (DNS) cyber-attacks

Abstract:

A method and system for detecting and mitigation recursive domain name system (DNS) cyber-attacks are disclosed. The method includes receiving DNS queries directed to a DNS resolver, wherein the DNS resolver is communicatively connected between at least one client and at least one name server; parsing each received DNS query to extract a hostname identified therein; updating at least one array of Bloom filters using the extracted hostname; computing a ratio of an unrecognized hostnames per sample (UPS) based on the contents of the at least one array; and determining if the UPS ratio is abnormal, wherein an abnormal UPS ratio is an indication of an attack.