Australian iPhone owners reported that their phones have been infected by a worm that has changed their wallpaper to an image of 1980s pop crooner Rick Astley. The worm’s capable of breaking into jailbroken iPhones if their owners’ve not changed default password after installing SSH. Once in place, worm appears to attempt to find other iPhones on mobile phone network that’re similarly vulnerable, and installs itself again. On each installation, worm - written by a hacker calling themselves "ikex" - changes lock background wallpaper to an image of Rick Astley with message: ikee is never going to give you up. Important: If you’ve jailbroken your iPhone or iPod Touch, and installed SSH, then you must always change your root user password to something different than default, "alpine". The worm’ll not affect users who’ve not jailbroken their iPhones or who’ve not installed SSH.
More info: Sophos