European security firm F-Secure on Wednesday detailed a new mobile phone trojan that attacks Symbian based phones with a new trick: the potential to jump to a PC if the phone's memory card is inserted into a computer. Cardtrap.A actually contains a payload of two Windows worms, Win32/Padobot.Z and Win32/Rays.

Padobot.Z attempts to copy itself using an autorun.inf file. However, the threat is minimal, F-Secure says. "To our knowledge, no Windows version supports autorun from a memory card, but it still might work with some Windows version and third party driver combination," said F-Secure researcher Jarno Niemela.