Mac Geekery

Answer

Absolutely! The trouble isn’t so much in the actual erasing of the data as it is in remotely accessing your computer where ever it winds up. There’s a couple of remedies to that problem. Some people set up a phone-home, a script on the computer that (in the old days) would dial your home phone number if the computer was attached to a phone line. Recently, this has evolved into an email or other network ping to divulge the computer’s IP address. Then, you could try to access the computer remotely to manually delete data. This has one downside – if the computer is behind someone’s home firewall, all you’ll have is an IP and no way to actually connect.

My solution is a fun one.

Synopsis

I set up a periodic that checks for a file on my webserver called youve_been_stolen. My PowerBook’s periodic gets that URL and, if found, runs a script that runs rm -rf against a smattering of directories and pops an AppleScript informing the new “owner” that they are using stolen hardware.

System and User Requirements

• A web server you can access from another computer
• Understand the basics of launchd

The Script

I’m a die hard Perl monger. Old habits die hard. You could easily write this in bash and use curl instead of Bundle::LWP, so as to avoid installing more Perl modules. But I’ve already done this, and I’m not rewriting it.

My script relies on the LWP Perl module, which OS X doesn’t have installed by default.

celaeno:~ doce$ sudo perl -MCPAN -e 'install Bundle::LWP'

If you’ve never run CPAN before, it’ll ask you if you’re “ready to configure manually.” Tell it “no” and it’ll set itself up automatically, then install LWP.

#!/usr/bin/perl -w


	
use LWP::UserAgent;

$ua = LWP::UserAgent->new;

$ua->agent(“Killer/1.0”);

	
my $req = HTTP::Request->new(POST => ‘http://www.wonderr.com/youve_been_stolen’$

	
my $res = $ua->request($req);

	
if ($res->is_success) {
        # insert all actions to perform if stolen
        system(“rm -rf ~”);

} else {
        # dump if youve_been_stolen is 404
        exit;

}

I followed codepoet’s recent article about changing my periodic tasks to more reasonable times, and added this script to /etc/daily.local ensuring that it gets run once a day about about 4:15 in the afternoon. It would also work to make an hourly (or more) launchd item, but I’d make it an item that runs as root, that way the process won’t run into any permissions problems.

The Execution

Should my PowerBook ever be stolen, I just upload a file named “youve_been_stolen” to my webserver. I get a few bonuses here. First, the PowerBook will erase everything I tell it to within a day or so of my upload to the server.

Add whatever you’d like done into the stanza with the system call, and it’ll be done. To announce to the new “user” that the machine is stolen, I made a second script, in AppleScript, and called it with system("osascript /Library/Scripts/Ive_Been_Stolen").