You can create a separate e-mail address (but not on gmail, there are good filters) and publish it as much as possible in all forums, chat rooms and social networks. Very quickly, this address will fall into spam databases and other bad databases, and you will receive dozens of spam emails every day in the Spam folder (some may fall into the Inbox folder). In these letters, most often malicious links are available on which you can download ransomeware for yourself, and sometimes the malware is simply attached to the letter itself as an attachment. But remember! You do everything at your own peril and risk! Be careful!
I wouldnt advice to torrent for samples, if you happen to seed so called clean torrent it can get you in troubles in very rare country specific situations, even its true the fake torrents can contain anything suspicious...its illegal to torrent( seed; = Share)
Cracks, normally is a tool used for that specifically as one breaks/bypass the license of a software, game etc.
Another more " healthy and sound " but less funny advice, would probably be to watch MTs AV testers and there work in the Malware Hub. Even join them and help out would of course gain one access to very nasty samples that easy could screw up ones PC, if wanted.