... but I will say 'resistant.' For whatever reason you choose, as yet OS X hasn't fallen to any public attack that hasn't required user intervention to install itself. I'm sick and tired of zealots crowing about how the Mac always falls first at the Pwn-2-Own competition when it has never fallen to an attack in the wild the same way while Windows is still the one that sees the majority of successful attacks year in and year out.

No, no machine is impervious, but for whatever reason, OS X is still proving to be the most resistant.