A security article caught my eye today because you don't hear much about Trojans or viruses that attack Macs. Here's an except from the article which really speaks to why this is important:
While the Trojan is relatively simple and not a big threat, two things came to my mind immediately: the bad guys are taking Mac now seriously – this is a professional attempt at attacking Mac systems (and they could have been much more damaging really). The second thing that folks at Sunbelt noticed (http://sunbeltblog.blogspot.com/2007/10/screenshot-of-new-mac-trojan.html) is that when they sent a sample to VirusTotal there were 0 (zero, nada, nilch) products that detected this.
A professional attack against Macs and no antivirus products were detecting it. Not only is this a scary prospect, but it is probably a precursor to more attacks. Let this serve as a reminder: Computer Security is important for everyone, not just Windows users. Heres a link to the article if you want to read more:
http://isc.sans.org/diary.html?storyid=3595