With the rising popularity of Macs, it was only a matter of time before hackers targeted Mac systems. A trojan called “Flashback” utilizing a Java vulnerability infected 600,000 macs and transmitted a user’s sensitive data such as passwords back to the person/group that deployed it.
Fortunately, Apple has released a fix for this and it should be pushed to systems. The update, “Java for OS X 2012-002,” is only available for desktop and laptop PCs running OS X Lion 10.7; Apple issued a similar update last week for both Lion and Snow Leopard, and the exploit was seemingly addressed properly the first time on the Snow Leopard OS.
Also just to be sure, you can also double check if your Mac is affected by the virus by following the instructions here.
Here’s also an interesting map on the breakdown of where the infections are happening.