Experts are warning of a new worm spreading across mobile networks via Symbian phones.

Fortinet’s threat response team warned on Monday that the worm, identified as SymbOS/Beselo.A!worm, is able to run on several Symbian S60 enabled devices. These include handsets such as Nokia 6600, 6630, 6680, 7610, N70 and N72 handsets.

After infection, the worm harvests phone numbers located in a user’s contacts lists and targets them with a viral MMS message carrying a SIS-packed (Symbian Installation Source) version of the worm. The malware also sends itself to mobile numbers located in China and to a particular mobile phone operator.

We would advise you that you never install an application of unknown origin, especially one you receive unexpectedly via Bluetooth or MMS.