Towns' worm, known as Ikee, threatens iPhone users who have jaibroken their phones to let them run unauthorised software. The .

Ikee doesn't do anything particularly bad - it changes the victim's wallpaper to a photograph of 80s singer Rick Astley and then seeks out other phones to infect. The worm does not affect most iPhone users; only those with jailbroken iPhones that are running a Unix utility called SSH (Secure Shell) with the iPhone's default password, "alpine", still in use, but its arrival heralded a minor boom in iPhone malware, being closely followed by two other infestations.

The second piece of malware harvested personal data from iPhones, including user email, contacts, SMS messages, calendars and multimedia files. More recently, a much more serious worm has been targeting jailbroken iPhones and adding them to a mobile botnet.

Towns is far from the first hacker to demonstrate his skill via nuisance malware and then turn legitimate, landing a lucrative job. But the move is sure to generate publicity and controversy (which may be the point).

Indeed, Sophos' Graham Cluley was typically quick to tell : "It leaves a nasty taste that he has been rewarded like this, yet has not even expressed regret for his actions."