It has been discovered that both Hulu.com and MSN.com have been using powerful supercookies to track online visitors user data. The supercookies are almost impossible to detect and can recreate user profiles even after a normal cookie has been deleted and are capable of stealing a users complete browser history in some cases.The data can then be used to see a visitors financial and health status and provide advertisers with considerably more detailed information than a standard cookie would divulge.

The websites use of the new supercookies was discovered by researchers at Stanford University and University of California at Berkeley. The supercookies are sometimes distributed through Flash content as cookies for this type of content are stored in a separate folder away from normal cookies, and are not removed when a user clears their normal cookies folder.

Once contacted about the new Supercookies Microsoft removed the code and explained,  "when it was brought to our attention, we were alarmed. It was inconsistent with our intent and our policy.” said Mike Hintze, associate general counsel at MSN parent company Microsoft Corp. Hulu has said that are currently investigating the discovery.

If you are worried about supercookies on your systems there are a number of ways to clean them off. Mac Users can use the Flush.app software, while Windows users can use CCleaner to remove most of the harmful cookies making the rounds. There is also a plugin for Firefox called BetterPrivacy which will help keep cookies out of your system.

Source: WSJ : Gizmodo