Given the millions of threats that Symantec products block every day, you might find it interesting to know which detection consistently holds the top spot. It’s not a worm such as the recent W32.Stuxnet or a virus like W32.Virut, or even one of our long-term generic detections, such as Backdoor.Trojan. The detection most frequently encountered by Symantec antivirus users is Tracking Cookie.

A cookie is a plain text file that stores data about your browsing session. While the term cookie seems harmless it comes with its share of pros and cons. Cookies can serve a useful purpose by allowing websites to track visitor information, allowing them to customise their advertising to customer needs. On the flipside, tracking cookies can be considered a privacy concern. A tracking cookie is a cookie which keeps tracks of all your browsing information and can be used by hackers and companies to obtain your personal details like bank account details, your credit card information etc.

The problem is that unlike traditional browser cookies, tracking cookies are relatively unknown to web users. Users may not be aware of the privacy issues these cookies pose. Tracking cookies are in the news as well, as some media companies that use them have found a way to resurrect deleted tracking cookies by using other cookies that are stored within Flash applications.

Symantec antivirus system scans can detect these “Zombie cookies” and remove them from computers. IT administrators and computer users are encouraged to have up-to-date, legitimate security software running on their system. Internet users should be wary of links in e-mails and IM messages since these are likely methods an attacker would use to prompt a user to visit a Web page hosting exploits and malware.