OS X and Security

OS X has a spectacular reputation for stability and security. At this writing, there still hasn’t been a single widespread OS X virus. There’s also no Windows-esque plague of spyware (downloaded programs that do something sneaky behind your back).

The usual rap is, “Well, that’s because Windows is a much bigger target. What virus writer is going to waste his time on a computer with 10 percent market share?”

That may be part of the reason OS X is virus-free. But OS X also was built more intelligently from the ground up. Listed below are a few of the many drafty corners of a typical operating system that Apple has solidly plugged:

  • OS X has always come from the factory with all of its ports shut and locked.

    Ports are channels that remote computers use to connect to services on your computer: one for instant messaging, one for Windows’ remote-control feature, and so on. It’s fine to have them open if you’re expecting visitors. But if you’ve got an open port that exposes the soft underbelly of your computer without your knowledge, you’re in for a world of hurt. Open ports are precisely what permitted viruses like Blaster in 2003 to infiltrate millions of PCs.

  • In OS X, no program (like a virus) can install itself without your awareness. You’re notified at every juncture when anything is trying to install itself on your Mac. In fact, every time you try to download something, either in Safari or Mail, that contains executable code (a program, in other words), a dialog box warns ...

Get Switching to the Mac: The Missing Manual, El Capitan Edition now with O’Reilly online learning.

O’Reilly members experience live online training, plus books, videos, and digital content from 200+ publishers.