This article applies to:

• all filters except inline SWG product

Question:

What is the Ultrasurf proxy software?

Reply

Ultrasurf is a proxy client, which is a program designed to allow end users to circumvent gateway security devices like web filters and secure web gateways in order to surf the Internet without restrictions.

Ultrasurf was developed by an organization called Ultrareach (http://www.ultrareach.com/), which was founded by a group of Chinese political dissidents.  Ultrareach continues to actively maintain and update Ultrasurf.  They designed Ultrasurf specifically to allow Chinese citizens to circumvent the Chinese government’s efforts to restrict Internet use in China.

The Chinese government has constructed a large and formidable Internet filtering infrastructure in order to prevent Chinese citizens from accessing sites that it believes represent an ideological threat to the Chinese Communist Party.  This filtering system is widely known as the “Golden Shield” or the “Great Firewall of China”.  Many large US-based technology companies have been complicit in its construction, as a contingency of doing business in China.  It is a formidable adversary, likely one of the most sophisticated Internet filtering systems in the world.

As a result, Ultrasurf is a very sophisticated piece of software.  It uses a distributed network of proxy servers, installed and maintained by volunteers around the world much like a peer-to-peer network.  It uses multiple schemes to locate the proxy servers in its network, spanning different protocols.  It uses port and protocol tunneling in order to trick security devices into ignoring it or mishandling it.  It also uses encryption and misdirection to thwart efforts to investigate how it works.

Ultrasurf is free and requires no registration, which makes it widely distributable.  It requires no installation and can be run by a user that doesn’t have administrative permissions to his computer, which makes it very portable.  It can easily be carried around on a USB thumb drive and run from there.

Unfortunately, what makes Ultrasurf an incredibly powerful tool for allowing political dissidents around the world to evade oppression also provides end users on private, filtered networks with a way to access the Internet that violates acceptable use policies and introduces liability to an organization.

UltraSurf is continually changing in an effort to circumvent filtering solutions, and the Trustwave security and development teams are continually trying to engineer solutions to block it.

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