Has anyone heard of or seen this virus?

I was online, behind a hardware firewall and ZA running, picked this one up. Not sure how; didn't click any unknown links, download anything, etc. Suddenly, my PC went totally out of control and VERY slow. The .pdf file opened after a strange error message popped up. Could barely get my mouse to the ZA icon to launch a scan. It found this virus, with the name HEUR:Exploit.Script.Generic. Also found a Trojan.JS.Redirector.ue virus in my Firefox cache.

Googling this filename didn't get much of anything, but several links had short text that said something about "totally virus free." (Sites like torrent.com. . .) Yeah, right.