Why would anyone waste their time creating a virus for the Mac? It would make more sense to target a PC since they dwarf the users of Mac.
I bet this was done by someone close to the AV company or the company that made the software that was pirated (so that it will scare others to not try and steal their software). Other than that no one wants to waste their time making a Mac virus.
It's ripe for picking, almost no AV in use. Get 1% of the users and you have a 300,000-strong botnet, a big one by any standard.
10 million new macs sold in Apple’s fiscal year, add to that the fact that the OS has been out in some form for 7 years - and how many millions of OSX machines are now online? Even if we said 45 million, would that not be an attractive target, since 99.9997% believe their machines are essentially virus and trojan-proof and thus run no form of antivirus?
That is why the “obscurity” argument just doesn’t fly...