This indicates an attempt to access UltraSurf version 9.6 and above.
Ultrasurf is an Internet censorship circumvention product, developed by UltraReach Internet Corporation, to bypass Internet censorship and firewalls using various protocols like HTTP Proxy, SSL, cloud servers and DNS. It was initially developed to bypass the Great Firewall of China. Ultrasurf is one of the most popular proxy application used today. It is a closed source software and the security assessments are done by third party experts.