Unsure if you fixed it but its a security flaw in Adobe PDF reader.
Its not actually a virus its a script (scareware) that apparently runs using a flaw in adobe pdf reader. (just dont click any links)
Remove the pdf reader (uninstall it) i had the same problem and someone else who had it also told me the fix .. If you use Firefox get Foxitreader for PDF's untill adobe fix the bug.
If your Browser stops working simply goto internet settings and untick Use proxy server as thats what it changes to aim you at the fake site.
The script for the Scareware i got was from the daily vote (DOFG) AVG didnt spot it since started using Avast which did spot it ..
Hope this helps.