Apple is no stranger to Microsoft-like patch cycles, and they’ve been coming with increasing frequency in recent months.

What the Cupertino, Calif.-based computing giant is not familiar with are viruses, especially the in-the-wild kind that are actively infecting its users.

The other day, I was talking to a Mac user about my job, what I write about etc. and his response was, “Oh I don’t have to worry about that stuff. I use a Mac.” I replied that that won’t always be the case, just you watch.

Sure enough, today came news that researchers had discovered the first-ever in-the-wild malware attack affecting the Mac operating system. It’s pretty harmless (the trojan changes DNS settings to redirect users to fake websites), but the event is hugely significant nonetheless.

Mac’s small market share - compared to Windows - has long shielded users for the ire of cybercrooks. But that protection is increasingly a thing of the past, especially as the platform sees more widespread adoption through mobile devices, such as the enormously popular iPhone and iPod.

Does this mean Mac users are going to have to run to their nearest anti-virus vendor to get help?

Probably not.

But does it mean they should stop thinking they are bullet proof?

Most definitely.

Just as an aside: I just IM’d my buddy Ryan, who has a Mac, to determine whether he runs AV on his machine. His response: “I don’t think so.”

Some Mac users are so clueless about security, they don’t even know if they have AV installed in the first place. It’s funny but I guess you can’t blame it.

In the meantime, if you’re not going to install AV, at least follow the common sense best practices of internet and email use. Don’t click on untrusted links and don’t visit untrusted websites.