Legit Reviews reports security researchers found that the newly discovered OSX/Crisis trojan that targets Apple Mac computers is a commercial malware package created by Remote Control System DaVinci. The trojan allows hackers operating it to spy on Skype audio traffic and record all conversations and phone calls, record IM messages in Messenger and Adium, spy on Safari or Firefox browsing, etc.
To be honest though, those spying functions aren't terribly unique to this malware. What is unique is that the malware is apparently a commercial malware package written by a company called Remote Control System DaVinci, which is apparently a play on the owner’s name and possibly a reference to the movie Hackers. "They gear their product towards government surveillance, though they have also apparently sold it to several banks and at least one other commercial company. Due to the cost (€200,000), this product is unlikely to be used by your average script kiddy in his parents’ basement." To avoid infection, as usual use common sense and run an internet security package to defend against attacks like this - yes this applies to Mac users too.