Lost Season 4 Episode 1 Torrent Download

/Lost Season 1/Lost - S01E02 - Pilot (Part 2).avi has a malware on it.. After having it partially downloaded, Avast detected it as a virus, I of course ignored it cuz well, how is it possible to get a virus from .avi right? Anyway I researched and of course it confirmed telling me it's basically a false positive and any virus that could go into an .avi extension is harmless.. Well, 10 minutes later, Antimalware Doctor installed itself (which is known as a pretty big virus), and I of course panicked and set Avast to do a boot time scan and I restarted only to find out it's too late, windows wouldn't run, avast wouldn't run.. dead.
I then formatted, re-installed windows, and tried downloading this torrent once again cuz I thought maybe there's a chance that a virus from somewhere else just attached itself to the .avi, but nope.. file reached 65% downloaded and WHAM!, Avast detected it again, this time I deleted it and the torrent before it started up again.
There are other torrents out there with that episode, I can't vouch for the rest, but Season 1 episode 1 part 2 is a bad file to download. I'll be downloading from someone else from now on.
And plz, no bashing at my comment, I know it sounds ridiculous that my computer got infected by a .avi file but there's really no way I can prove it, I can just make the warning and then 'walk away' hoping someone listens.