Mention Viruses to a Mac user and the response will often be… well, smug. Many Mac users believe that viruses and other malicious software are a Windows problem. Apple hasn’t done much to discourage that notion, not even to warn users when real threats are afoot.

Recently someone launched a bit of malware targeted directly at Macs. The program would lurk on Web sites (I think that’s where it came from, anyway), and flash up a message “Your computer is infected with a virus! Download our software to clean it up!” The software to install had a noble, protective-sounding name. People followed the instructions, and infected their own machines. Before long a couple similar threats appeared, including a much worse one that required less participation by the owner of the computer.

Now, it could be argued that only an idiot would fall for something like this. I occasionally see alerts that my windows computer is infected and I must download something to fix it — even though I’m on a mac. You don’t have to be around the Internet very long to learn not to trust strangers. Unfortunately, there are a lot of idiots, and even more newbies who have not learned that hard lesson.

A couple of days ago at work I got an email addressed to all Apple employees telling them not to fall for “Scareware”. The evil had been circulating for a month or more before Apple even alerted its own employees about the threat. Yesterday Apple released a security update that removes this particular family of bad guys and takes some measures to make similar attacks more difficult in the first place.

But there’s one thing no virus protection can do: prevent the user from giving permission to dangerous software to run on their system. Once the user says the software is OK, that’s it. Mac users’ feeling of immunity from harm could make them more gullible; they’ve never given much thought to how they would react when confronted by an urgent message like the ones in this latest outbreak.

So, fellow Mac users: Don’t be stupid! Almost as important: Put that smug attitude away. Your day is coming, sooner than you think.