The computers affected by Cryptolocker at this college computer laboratory were Linux systems. I asked whether or not they were running WINE or anything like it, and the answer was no.
I have read of an imitator that does run on Mac that looks like Cryptolocker but doesn't actually encrypt the files. This is written in Java so it could also infect Linux if you were to be su when it arrived. Shouldn't routinely be the superuser. Not prudent.