Do I need an antivirus program for my Mac?
For now, it is possible to function without an antivirus program in your Mac OS X. That’s because Mac OS X is built on the Darwin (BSD) kernel, which is relatively stable and secure, and Windows’ virus does not work in Mac OS X. Mac OS X is, of course, not perfect. There’s always a chance that a new kind of virus can attack Mac OS X, but it doesn’t exists yet.
Anyways, most antivirus solutions for the Mac are actually aimed at REMOVING Windows virii fron the infected files before passing them on to Windows users. In a sense, they help to protect your Windows boxes and/or your windows-using friends. You are therefore using up your Mac OS X resources to help stop a problem that plagues Microsoft Windows users! You decide for yourself if that’s a worthwhile effort.