shutdown piratebay was good recently i download a software at piratebay and then i get viruses in my pc 
Who told you to download unverified torrents? First you need to check the user comments and the user reviews. If the file actually contains trojans or spyware, then usually the users will flag it in a matter of hours. I don't know much about PirateBay, but in 1337x, there was an option to download only the verified torrents.
There is also comment section where people post warnings if the file is infected or torrent is fake.
If torrent is uploaded by anonymous/unknown uploader and there is zero comments then use you common sense.
The best idea is to open the file in sandobox environment.