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.
Rustock is a Trojan application that uses advanced rootkit techniques to hide from users. Once installed, it can download additional malware and also display annoying and intrusive advertising. Removal is highly recommended.
Technical details (How to remove Trojan.Rootkit.Rustock(pop up))