Disable Automatic Downloading of Malware Definitions List in Mac OS X

A recent anti-malware Mac OS X security update was released that defaults to automatically downloading and maintaining an active definitions list of known Mac OS X malware threats. This list comes from Apple and is likely a very small file that is transmitted to your Mac, imposing minimal bandwidth usage.

For 99.99% of users, you should keep this option enabled and get the definition list automatically, it helps secure your Mac.

How to Opt-Out of the Updated Malware Definitions List in Mac OS X

This is not recommended and could expose your Mac to security vulnerabilities. If for whatever reason you do not want to automatically download the daily updated Mac malware definitions list from Apple it’s very easy to disable. After the Security Update is installed, do the following:

1. Launch System Preferences from the  Apple menu
2. Click on the “Security” panel
3. Under the “General” tab deselect the checkbox next to “Automatically update safe downloads list” – note this may leave you vulnerable to future variations of malware

Some of you are probably wondering why anyone would want to opt out of receiving the definition list. Maybe it’s to test the affects of malware on a crash box, maybe you have limited bandwidth or connectivity options and don’t want to use any unnecessary data, maybe you don’t like automatic communications with the outside world, maybe you don’t care about malware at all because it’s really not that big of a problem, who knows.

Again, this is not recommended to opt out of unless you know what you’re doing, but it’s nice to know you have the option to if necessary.