The BBC today reported that there is a new iPhone worm which attacks jail-broken iPhones, as did the Rickroll worm in Australia last month.
This one is malicious, not just annoying, and targets Dutch customers of ING Bank:
It is specifically targeting people in the Netherlands who are using their iPhones for internet banking with Dutch online bank ING.
It redirects the bank’s customers to a lookalike site with a log-in screen.
The worms work because they target the root password for the ssh (“secure shell”) function, which becomes vulnerable when the phone is jailbroken; many iPhone users, even those with jail-broken phones, probably don’t even know what “ssh” is, because it’s a Unix/Linux thing.
I use ssh frequently, often several times a day, to avoid getting up and walking into the next room to do something directly on another computer, but my passwords are not in the wild.