Two Mac trojan outbreaks were spotted in the past week leaving several people, including myself, to wonder if the tipping point for the Mac malware epidemic has arrived. Frankly, I don't know, but I tend not to think so. I do think, however, that Mac malware will now become endemic amongst the high-risk groups such as file-swappers. This past week a trojan claiming to be the latest iWork release was spotted on file sharing networks. Shortly thereafter, a similar trojan was sighted that masquerading as a crack for Photoshop CS4. Both events are making some people question whether or not the Mac's long tenure as being a malware-free system is coming to a close and to face facts and install AV software.
The short answer is if you are a relatively well-behaved computer user, probably not. Mac malware is not endemic amongst the general population due to these events. The trojans of the past week is not self-propagating beyond the high-risk population, namely file swappers, and is relatively easy to find, analyze, and remediate. This is in stark contrast to PC users who have been hit with the Downadup/Conficker worm, which propagates via three orthogonal vectors and includes one remote exploit, and actively prevents you from visiting websites that contain remediation tools.
I do think the relative halcyon days of malware-free Macs are coming to an end. Anyone who is currently infected by the new malware will remain infected without direct human interaction due to the lack of any automatic mechanism for the identification and removal of malware. That means there is a non-zero population of Mac users who are now compromised and will remain compromised unless they either clean their machine or they buy a new system. Sounds familiar, right?
The question I want answered is whether or not the monetization rate of compromised Macs is sufficient for the malware authors to continue to pursue the platform. If not, these events will be a blip on the radar; otherwise, Mac owners better keep their Time Machine backups up to date.