Mac OS X Snow Leopard antivirus features
Apple has long maintained that Mac users don't need to worry about viruses and other malicious software, so the fact that its latest Mac OS X, Snow Leopard, includes new antimalware protection is quite a turn of events. Don't get too excited, though; it is by no means a full-featured antivirus program.
Out of the box, Snow Leopard will be able to detect just the two most common Mac Trojans: RSPlug.a and iService. The feat is accomplished by checking malware definitions stored in a new .plist file in the /System/Library/CoreServices/CoreTypes.bundle/Contents/Resources folder. (Using the Mac's Software Update service, I assume that Apple will push definition updates to this file to add new malware signatures in the future.)
However, one glaring antimalware limitation is that only files downloaded using a few select applications, such as Safari, Firefox, iChat, Entourage, Mail and Thunderbird, are scanned for malicious code. This means that files obtained using any other applications, such as torrent clients or peer-to-peer (P2P) software, which are probably more likely to be sources of an infection, are not checked. iService, for example, piggybacks on pirated copies of iWork '09, which are downloadable from file-sharing sites. In addition, files that are on CDs or USB drives are also not scanned, so Macs can still be infected with either of these Trojans.
