(PhysOrg.com) -- iPhone users in Australia have been hit during the last few days with a worm called "ikee". The worm replaces the default wallpaper with a difficult to remove picture of British singer Rick Astley and a message "ikee is never going to give you up," a reference to Astley's 1980s hit song.
The worm is the first detected that specifically targets the Apple iPhone. The worm only affects users who have "jailbroken" their phones to allow them to run authorized software. It appears to spread by searching an affected phone's contact list for other jailbroken phones. Users must have installed the Unix utility SSH (secure shell) and retained the default root password: alpine. SSH allows people to connect to an iPhone via the Internet.
Spokesman for security firm Sophos, Graham Cluley, said the worm does not appear to have spread outside Australia. It does little more than irritate affected users, but it does highlight the vulnerability of jailbroken phones, and there is a danger the code could be turned into a more malicious attack.
The worm was written as a practical joke by Ashley Towns, a 21-year-old unemployed programmer from Wollongong in New South Wales. He wanted to make the point that users ought to change their password, especially if they are using SSH. Towns said he was surprised the worm had gone as far as it had, and he had not considered any possible ramifications of the prank.
The worm is a variation on a well-known prank called Rickrolling, in which victims are tricked into inadvertently playing a video of the song "Never Gonna Give You Up" or seeing a picture of Rick Astley.
In another attack on the iPhone, a Dutch hacker used port scanning to identify jailbroken phones running SSH with the default password. The hacker replaced the wallpaper with what looks like an SMS alert that demands money in return for instructions on how to secure the iPhone.
The two attacks should serve as a warning for users who jailbreak their iPhones that it makes them vulnerable to attack.
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