Adware:Adware (or spyware) is a small program that is designed to show advertisements (in various form and degrees of intrusiveness) on your computer. It often reports personal information back to its owners. As a result your sense of privacy can be violated.
Trojan.FavAdd is a Trojan program that installs itself on your computer without your knowledge or consent, often through browser exploits. Once installed, Trojan.FavAdd will add numerous shortcuts to crack, serial, and other software piracy-related websites to your IE Favorites. Trojan.FavAdd will also add an IE button that points to the crackspider.com search engine. Trojan.FavAdd will also hijack Internet Explorer search pages.
Technical details (How to remove Trojan.FavAdd(pop up))