Worst nightmare of all: Mac OS X targeted by Trojan and backdoor tool

ZDNet article

The article pointed out that Mac OS X is vulnerable for trojans attack. Although it's really not as lethal as virus, it's still something that needs to concern about. I basically want my Mac to be in perfect health. I do begin to feel that it's just a matter of time when hackers and viruses will attack Macs. There's a serious concern over this matter as I and most users don't have virus scanners on their precious Macs.