Here's a little rule of thumb I go by... If you didn't buy it, and you need a key, find it yourself. Consider yourself lucky enough to get that kinda' software without paying for it, and don't expect everything to be handed to you as easily as that. Serial numbers are easy enough to find, and trojans are just a risk you're going to have to take if you're going to be pirating software.
Another rule of thumb I go by is not to pirate software if you're going to make profit from it at any point, so I'm just assuming you're not.