GGJstudios
macrumors Westmere
Of course it's possible to infect a Mac with malware by installing something you shouldn't, such as pirated software that's been infected. That's why you should only install software that you acquire from reputable sites.So... at the end of the day it is still possible to get infected if you agreed to install something even though you thought it was legitimate?
Don't install something just because someone sends it to you. If they recommend an app, research it and download it directly from the Mac App Store or from the developer's site or from a trusted site like Cnet.
Before you open an attachment, be sure what you're opening. If you expect to open a document and instead are presented with an install screen, quit the install and delete the file. If you exercise reasonable caution, you don't have anything to worry about.
Remember, there are only a handful of trojans in the wild that could affect your Mac. Other than the recent MacDefender nonsense, which is easily spotted, encountering them is quite rare for the average Mac user.