Try the Pirate bay,
http://thepiratebay.org/search/cubase%20sx/0/99/0
Read the comments on the torrent pages for instructions , tips , and whether or not it's 'real' and virus free.
And then scan anything you download with your AV program.

or join a 'news group' but then you pay per month for the privilege.

Hey If anyone can get cracked anything its my cousin! Check him out at www.thebigguyconnor.blogspot.com and he'll fix you up nice and good. (Go to the contact us page to get his email and stuff, or post a comment on the blog...he'll make a really nice post for you.)
If you need anything cracked...contact connor lol

Oh wow pleeassse this is dangerous posting about cracks and software piracy where everyone can read it... Its illegal! Please do not post requests like these... The whole site could be shut down for providing this information (not likely with thepiratebay itself STILL up and running after a couple court cases) but still. Hmm

ps paps I like your new do and is that a waterpipe??