sex411.tv script in my code ??? virus

As I debug my project C#/Visual Studio Web Developer i get [dymanic] files.
Google ads, tracking cookies, pages like "Welcome to SEX411.TV" and so on..

Has anyone any idea of what is going on.

The only thing I can think of is that I downloaded the Ajax toolkit for VS a while back, and that my Norton has been out of date for a while.. but.. inserting code into my projects.. ??

Any ideas?

Thanks