Last summer Apple users were slapped with the notion of a real infection that was rapidly spreading through Mac operating systems.
Other variants soon followed, and now another infection is making the rounds.
PC World reports a vulnerability associated with Java is being exploited by cybercriminals and aimed at Mac users. The malware is a new variant of last year's Flashback malware, according to F-Secure, an antivirus company.
An unpatched Java vulnerability in Apple operating systems is the gateway to the infection. One of the significant problems is that no user action needs to occur for this latest version of the trojan, dubbed Flashback.K, to infect. Users can get infected by simply visiting a website on this go around, reports MacWorld.
In previous versions the malware masqueraded as an Adobe Flash Player update and required a user password to be entered, a later version dressed itself up as a Mac software update.
"If you haven't already disabled your Java client, please do so before this thing really become an outbreak," F-Secure said and shared disable instructions.
In May 2011, the first construction kit for Mac OS X trojans emerged in the form of a scareware called MacDefender. This malware, which resembled the type of scareware that has plagued Windows users for years, rapidly spread through the computers of Mac users caught off-guard. Since then several different types of malware aimed at Macs have emerged.
Windows users have been patched against this current Java bug since Feb. when Oracle made the fix, but at this time Mac users are vulnerable since Apple distributes these updates. Historically, Apple's patches are behind Windows when it comes to Java security patches, reported MacWorld.
Over the past year, attackers have been more aggressively going after Mac operating systems, which occurred at the same time Apple gained approximately 16 percent of the OS market in several countries, lending credence to the theory that cybercriminals target the products users most employ.
While Mac malware is not as prominent as Windows malware, it's clear trojans and other nasty bugs are not just for Windows anymore.