FireWire and filched files

Reader Brian is insecure about his Mac’s security. He writes:

I have heard that all the information on my hard drive is easily accessible to any one who “comes by” with another Mac and a FireWire cable. Would you explain what threats an unattended sleeping MacBook might be exposed to?

What you’re describing is the possibility that someone could grab your laptop, string a FireWire cable between it and their computer, restart your MacBook with the T key held down to boot it into FireWire Target Disk mode, and pull data from your drive, which is now mounted on the evildoer’s Desktop. A hard drive mounted this way is wide-open as FireWire Target Disk mode doesn’t respect permissions, so you have reason to be concerned.

You can protect yourself, however. The means for doing so is firmware password protection. All Intel-based Macs allow this form of protection as do the PowerPC Macs as far back as the eMac, original FireWire PowerBook, Power Mac G4 (AGP Graphics), all iBooks, and slot-loading iMac. With firmware password protection in place, a Mac can not be booted into FireWire Target Disk mode.

To protect your Mac in this fashion you’ll need the Open Firmware Password application (for Mac OS X 10.1 to 10.3.9) or the Firmware Password Utility (OS X 10.4 and later). You can download the Open Firmware Password application here. You’ll find the Firmware Password Utility on your Mac’s installer disc by following this path /Applications/Utilities.

After implementing this protection you’ll be required to enter a password to access your computer.

Note that this isn’t completely foolproof. For example, if someone has taken off with your laptop, all they need to do to get around this form of protection is remove the drive from the computer and pop it into a FireWire enclosure. For this reason it’s a good idea to either keep your laptop with you or physically secure it so no can walk away with it.

Encrypting the data on your computer isn’t a bad way to go either if it’s imperative that your data remains secure. Apple’s FileVault can do that for you on a broad scale—encrypting your entire Home folder. Or you can easily create encrypted disk images with C-Command’s $20 DropDMG utility (you can do the same thing for free with Apple’s Disk Utility but it’s a more time-consuming process).

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