Let me make one thing clear. There is a perception that the Apple Mac cannot have malware. This is incorrect.

Apple Computer posted a note on its support site late last month, and removed it this week, which encouraged people to use anti-virus software. The presence of the note has caused much consternation among the media, the blogosphere and the Apple faithful, the latter of which have long proclaimed that Apple does not need anti-virus software. The notice read, “Apple encourages the widespread use of multiple antivirus utilities so that virus programmers have more than one application to circumvent, thus making the whole virus writing process more difficult.”

In fact, Apple should be praised (initially at least) for issuing such a common-sense notice, but spanked for taking it down. No security expert in his or her right mind would recommend going without anti-virus software, regardless of platform. Those who have drunk the Apple Kool-Aid and believe that their machines are impenetrable are making a big mistake. An unprotected Apple is a disaster waiting to happen–sooner or later, an attacker will take a bite out of it.

It’s true that there have been very few viruses targeted at the Apple OS, although that is largely because of market share, and not technical superiority. Attackers want to cast the widest net possible, so they write Windows viruses, because there are more Windows machines. Cute television commercials aside, that’s really all there is to it. And besides traditional viruses, there is a greater shift among cybercrooks to Web-based attacks designed to steal passwords and other data.

It’s very curious that the message disappeared shortly after it was put up–more than likely because it conflicts with Apple’s ad campaign that implies that only Windows PCs need antivirus software. Ultimately though, the threat is very real, and will only become more serious as time goes by. Viruses and other malware threats cannot be ignored, and if Mac gains more market share–which is presumably the company’s goal–there will be viruses. You can count on it.