While what was said to be the first iPhone worm merely annoyed jail-broken iPhoners by installing Rick Astley wallpaper, a second is said to be "clearly malicious".
Security company F-Secure has discovered the worm that's specifically targeting those in the Netherlands using online bank ING, reports the BBC.
The malware - that again just affects SSH-enabled, jail-broken modified iPhones - redirects ING customers to a lookalike site with a log-in screen.
As well as the immediate financial implications, the worm could see such handsets accessed and controlled remotely.
"It's the second iPhone worm ever and the first that's clearly malicious - there's a clear financial motive behind it", F-Secure research director Mikko Hypponen told the BBC.
"It's fairly isolated and specific to Netherlands but it is capable of spreading".