8e6 Technologies has reported that it has blocked a common exploit used to bypass many of the popular web filtering products in the market.

The "anonymisers" or "web-based proxies," are rapidly becoming one of the most common Internet filtering and blocking work-arounds in the enterprise and pose a significant security risk to both corporate networks and the users who exploit them.

Unique in the security marketplace, 8e6 Technologies' solutions filter unsuitable content using a database of IP addresses and URLs together with Intelligent Footprint pattern recognition technology (IFT). IFT uniquely allows 8e6 to detect encrypted proxy servers, anonymisers and tunnelling software, such as that recently loaded onto liverbeat.com, ultimately preventing use of public proxies to bypass web filters.

"8e6 Technologies' filtering solution provide a level of protection previously unseen in the marketplace - zero-day protection against Web proxy use in the enterprise. Traditional Internet filters such as Websense and SurfControl can only block encrypted proxies by classifying the URL in a database. This means that they may not catch and block a proxy exploit like Liverbeat.com immediately, placing companies at considerable risk from employees accessing unsuitable or malware-riddled content. Some network administrators may not even be aware that their users are bypassing the existing Web filter because the latest proxy software is so effective at hiding the user's activity," said Eric Lundbohm, Vice President of Marketing at 8e6 Technologies.

Public proxy scripts are widely publicised on the Internet and popular mailing lists. PHProxy is one of the most popular scripts used to create public web proxies, with thousands of sites using this and others such as Proxify, Circumventor and CGIProxy.