For the last few days, some jailbroken iPhone users have found their home screen background a little different than they remembered. A hacker, going by the name "ikee," created a worm that changes the home screen background on jailbroken iPhones whose owners failed to change the default password after installing SSH. Simply jailbreaking your iPhone will not make you vulnerable to this sort of hack. The iPhone OS, in general, is also immune to this hack. Still confused? Let's back up a bit.

On jailbroken iPhones, SSH is installable with a package from Cydia that allows you to connect to your phone and make changes to the filesystem. It does this by logging into the root user with the password "alpine." After installing SSH, it is always recommended that you change "alpine" to the password of your choosing. This hack can only affect people who chose not to change that password -- no one else.

This hack originated in Australia, the home country of ikee, and has possibly spread to other iPhones in other countries, but we've been unable to verify that. A gentleman by the name of JD held an interview with the hacker over IRC and posted it to his blog. In ikee's own words, here's how the worm has spread:

...The code itself is set to firstly scan the 3G IP range the phone is on, then Optus/Vodafone/Telstra's IP Ranges (I think the reason Optus got hit so hard is because the other 2 are NAT'd) then a random 20 IP ranges. I'm guessing a few phones hit a range that another vulnerable phone was on.

Basically, once your phone is infected, the worm starts looking for other iPhones on the cellular network that use the root:alpine combination. Once it finds another vulnerable iPhone, it installs itself and begins the process again... and again... and again.

Luckily for the jailbreakers in the audience who may have been affected, there's really no harm done -- at least not with this version of the worm. According to the hacker, this was more of an experiment than anything else. The worm changes your background and then disables inbound SSH, which is a good thing. If SSH was left turned on, a similar worm could follow along but conceivably do much more damage. For instructions on how to delete this worm, read JD's interview with ikee. I would recommend reading the interview just for the information it presents; I found it pretty interesting. If you've got a jailbroken iPhone or iPod touch and you've never changed the default device password, now's the time. Here's how, if you are using terminal:

Type: ssh root@(iPhone IP address)
When prompted for the password type: alpine
Now you're connected the phone...
type: passwd
It should then prompt your for a new password -- type one that you'll remember. There's no easy way to reset it if you forget it.

That's it. Please remember to be responsibly secure with your devices. Hackers like ikee are troublesome, but this could have been much worse. While I don't personally condone his actions, he's prevented a lot of people from being vulnerable to more malicious attacks later down the road.

Thanks, James!

Everyone's favorite battling invertebrates are coming to the iPhone and iPod touch very soon -- the game was actually announced a little while ago, but Team 17 now says the game has been sent off to be examined by Apple's eyes, and so, as long as it doesn't have any objectionable content (you can't object to exploding sheep, right?), we'll see it up for download very soon.

Exciting. Unfortunately, I'm coming off of a Worms 2 purchase on Xbox Live, so I'll probably be passing on this one, but if you haven't had a Worms fix in a while, the video on the next page shows what Team 17 is saying over on their Facebook page: it's "a full console-style experience," with extra options, including probably the ability to play your own music as you play. Multiplayer will only be pass-to-play to start with (bummer!), but they're hoping to add in both Internet and Bluetooth local multiplay at a later date. And there's no official word on price yet, but we should know it soon: look for Worms on an iPhone near you.

One of the long-standing major appeals of the Mac OS has been its relatively small and low-impact ratio of serious security vulnerabilities and virus attacks. Users wear it like a badge on their shoulder, and even Apple has jumped in by flat-out bragging about Mac OS X's security with their latest Get a Mac ad campaign.

While the debate surrounding exactly why the Mac has earned this reputation has raged at least since the term 'trolling' was coined, I'm a bit more interested in bending the space-time continuum and asking you, dear readers, a hypothetical: what would happen if a truly malicious Mac OS X virus were to break out in large scale? I'm talking about something along the lines of the Sasser worm, which grounded some Delta Airline flights, brought many other companies to their knees, and is estimated to have caused billions in damage.

I know Apple's machines aren't quite as integral to the various operations of our society and businesses like Windows and Linux are, but it would be hard to argue that a good portion of of the Mac user base doesn't care about the security of their chosen OS. With this in mind, I wonder: would you keep your Mac in a day and age when 3rd party virus and security tools become a basic necessity of Mac OS X? Would you bite the bullet and buy Norton Virus Mega Security Bundle Premium 2007 beta 5? Do you think all those switchers - reeled in by Apple's "We don't have any viruses" Get a Mac commercials - would become crippled in disillusion?

What say you, TUAW readers. How large of a hole in Apple's security record would be 'too large'?

This week's podcast involves Dan Pourhadi and the C4 developer shindig he attended, those exclusive Leopard screenshots we nabbed, iPod viruses and the corporate blame game, and we round off with Apple's preliminary 4th quarter earnings results. Dan and I kept things short this time around, as the podcast rounds off at just over 20 minutes and 18.6MB.

As usual, you can grab the podcast via a direct link, our podcast RSS feed or in the iTunes Store podcast directory. Enjoy the show.

Update: It seems there's a bug in our iTS feed preventing from getting this latest episode, though our other links for accessing the podcast are working just fine. We'll keep you posted.

Every time I write about Mac security the comments fill up with people telling me that I am an idiot (actually, come to think of it, that happens with most of my posts). Therefore, I thought some of you would enjoy this post from Symantec that which states categorically that there are no known file infecting viruses for OS X.

Hurrah! Macs rulez!! W00t!

Hold your horses, spanky. Todd Woodward, the author of the post, rightly points out that while there are no viruses for OS X there are worms, rootkits, and vulnerabilities in the OS itself. So, it is like I always say, Mac users might not have to worry about viruses now but that doesn't mean that OS X is somehow magically immune to viruses.