Virus or Trojan, I don't know!

Alright. I quit torrenting a while ago. After I quit I reformated. From there on out I downloaded everything safely (No limewire/ares/etc.) But a while ago I got what I thought was a virus. I would go onto Firefox and the pop up to download pops up. It says continue to download 709.psd (nntoz.info). I got scared sh_t and reformatted. That was a few months ago and yesterday it happened again. I said Fork it, and downloaded it and opened it in adobe reader and it would just freeze and not load. So I googled and found this

http://safeweb.norton.com/reviews/41454

What is that? I don't get it. Is that a website warning you or something? Is it spyware or something? After downloading it I scanned it and it was clean.. So wtf could it be?

Thanks.

Link does redirect to Norton home.

.psd is a photoshop extension...
.pdf is adobe reader.

Google pretty much does not give anything when i search for nntoz.info.
Also try to scan your whole system for viruses.
I doubt this will be a virus though, more likely adware (that got earlier on your pc through driveby downloads).