A new malware variant is doing the rounds. Calling itself “Apple Security Center”, it tells you your Mac is infected. It isn’t infected. But as a counter showing the number of viruses “found” rapidly rises, it will offer to clean your computer. Don’t agree to let it!
Oh, you did. Damn. Well now you are infected.
It’s like inviting a vampire in. Modern computers are designed so that software can’t just install itself, it needs interaction from the user. So malware (that is, evil software) can’t do any harm until you give it permission. Now Mac and Linux are more common, and Windows is a great deal tougher than it used to be, malware is increasingly forced to focus on the one major remaining weakness of all computer systems. This is what techies like to call the PBCAK – the Problem Between Chair And Keyboard. In other words, you. Sometimes called scareware, things like “Apple Security Center” attempt to mindgame you into infecting your own computer.
Stop and think. It’s a Mac, it is quite to very unlikely that it has a virus. And anyway, who the heck is in any position to know what’s on your computer? If you did not install an antivirus program – and even now you really don’t need to – then you will not get virus warnings. Not real ones anyway.