Keeping Your Mac OS safe

One of the best things about Mac OS X is that it has some very basic protection against malicious downloads, which means you don’t have to worry about malware entering your computer when you download an application or open an attachment in an email. You see, every time you download an application via Safari or an attachment in Mail and try to open it, Apple checks the file against its “safe downloads list” (sometimes called “XProtect.plist” after its file name) to see if it contains any known Mac malware. Plus, Mac OS X also checks for updates to this malware definitions list on a daily basis! However, if you’d like to do the updating by yourself, here are some ways in which you can:

Method #1.

  • Click on the Apple menu and select “System Preferences…”
  • From the main window, click on Security and then on the General tab.
  • You’ll see a lot of options, one of which is “Automatically update safe downloads list”. Uncheck and re-check the box next to it. (You may need to click on the lock and type an administrator password first.) If you don’t see this checkbox, make sure you’re running either Lion (v10.7 or later) or the latest version of Snow Leopard (v10.6.8).

This is the simplest technique you can use to update the list. This technique, however, doesn’t give any indication of whether the update has actually completed. If this isn’t okay with you, you might want to try out method #2.

Method #2.

There’s a freeware app (created by Adam Christianson of The Mac Observer) called the Safe Download Version. Once you run it (after you’ve downloaded and installed it, of course!), it tells you the version of your currently installed definitions and their release date, lets you check for updates, and notifies you whether you already have the latest version installed or if a new update has been applied.

Method #3.

You can also check for updates by running XProtectUpdater via a Terminal command.

Well, these are some ways in which you can keep your “safe downloads list” updated. But you shouldn’t let your security stop at that. In case you didn’t know, Mac OS X only detects a limited number of specific malicious downloads from about ten different types of Mac malware. Plus, Apple’s built-in protection does not defend against a wide range of threats such as malware copied over a network share or from an external drive, malicious JavaScript code embedded in Web pages, Microsoft Word or Excel macro viruses, malware downloaded with an application that doesn’t utilize Apple’s safe downloads protection, or malware that already exists on your hard drive. To make things worse, Apple’s download scanner also doesn’t offer any protection against malware for other platforms such as Windows. So if you’re worried about your Mac’s defenses, try taking its security a notch higher by installing the free Sophos Anti-Virus for Mac Home Edition.