In the same fashion that many Linux distributions aren't targeted by viruses and malware, Apple's proprietary Mac OS X platform was never much of a good target for hackers to begin with. The platform has only gained a lot of traction in the past four years and is a more recognised name globally, synonymous for some with extreme quality and ease of use. But for others, OS X has become a viable target.
Just a last year, in August, Apple was alerted to a botnet building up among their customer's computers, at its height claiming over five hundred thousand desktops under its control in under two months. By the third, another hundred thousand desktops and laptops were under hacker's control and there wasn't any word immediately from the Cupertino company about how they were going to fix it. Oracle's Java was the source of the vulnerability and it was patched by the company four months later in February - but Apple never pushed out the update immediately, choosing o rather wait and teat it out before pushing to their servers last week.