Antivirus makers are locked in an eternal two-step with virus coders, blocking today’s virus only to wake up tomorrow to find a new variant out in the wild. Should Apple follow suit, and begin the sisyphean task of trying to stay ahead of malicious coders, knowing the end result is, in essence, eternal gridlock? Or, could there be another way to keep the Macintosh the virus-free paradise longtime users have come to know and love?

Less than eight hours (time stamped 9:24 pm last night) after Apple released Security Update 2011-03 for Mac OS X Snow Leopard to deal with MACDefender and related malware, the developers behind the apps created a new variation that is able to slip paste Apple’s updated security. To avoid having your Mac infected, use caution when downloading suspicious software.

In a new support document from Apple, the company acknowledges the existence of malware known as MACDefender (along with other variants) that acts as anti-virus software in an attempt to steal a user’s credit card information by persuading them to register the software. Apple has also stated that an update for Mac OS X is on its way to get rid of the malware and warn users should they be brought to a web page where the malware is present.

A new security threat targeting Mac OS X users has been discovered disguising itself as anti-malware application “MACDefender” (which is in no way affiliated with MacDefender, creators of popular geocaching software). The malware makes use of Safari’s feature which automatically opens files which it deems “safe” after a download, triggered through JavaScript which automatically downloads the file once you visit the malicious web page.

Remember the Boonana trojan horse that was in the wild for Mac OS X last month? A variant—the trojan.osx.boonana.b—has now been discovered that acts in much the same way as the original malware. SecureMac has been able to identify two+ websites that are hosting this trojan via update code for the malware. This is a little different from the original trojan which tricked users into running and installing the malware themselves.

In a press memo, Mac security specialist Intego announced the discovery of a spyware application connected by a few freely available Mac OS X applications. This application is apparently capable of activities from “scanning files to recording user activity, as well as sending information about this activity to remote servers and opening a backdoor on infected Macs.” Labeled as high risk, this malware has been existent in a different form on Windows since 2008 and is usually installed via misleading text about a “market research” program.

Yes, we’re all aware that the Mac is pretty solid against viruses, but it’s not impervious. Evidence of this comes from a report at 9to5Mac in which they state, “Security researchers at Symantec have uncovered what they suspect may be the first Mac OS X botnet launching denial-of service attacks.” Of course, to get it, you have to bypass Apple’s warnings and break the #1 rule of downloading content from the web, but you know, malware nonetheless.