Q&A: Does an air gap protect from malware?

Q As I do not have any anti-virus protection installed on my Mac Pro, when I need to check suspicious mail I physically disconnect it at its Ethernet socket. Is that a good idea, or will it cause me problems?

A It will certainly protect you from any mail which might contain Trojan material trying to hijack your Mac to a malicious site, for instance. However, unless you set your mail client not to download attachments, you could still receive a malware payload in an attached file. This will also physically wear your Ethernet cable and socket, increasing the risk of hardware failure.

If you want to block software from phoning home or hijacking you, try Little Snitch, which will not cause any more wear to your network connection. If you want good and reliable tools to help protect your Mac from modern threats, visit Objective-See’s collection.

Updated from the original, which was first published in MacUser volume 28 issue 16, 2012.