The official Bit Torrent 3.3 download is fine if you get it from the official site, but there are some bogus ones floating around which are riddled with spyware.
Taken from there FAQ:
Does BitTorrent contain spyware or adware?
No, BitTorrent contains no spyware, adware, or any other kind of -ware.
Some warez sites are distributing spyware-wrapped versions of the BitTorrent installer. Please only download the BitTorrent installer from this site. I'm considering legal action against sites which misrepresent their hacked installers as the official one.
http://bitconjurer.org/BitTorrent/download.html is where I got mine from, assuming nothing has changed in the last 2 weeks this should be spyware free.
Hope this helps mate.