More words of warning have been given regarding the Symbian OS and Series 60 UI-targeting malware known as Cabir, where it is being warned that the mobile phone worm is expected to spread significantly in the coming months, as a result of the leaking onto the internet of the source code for this malware.

The upshot will be the arrival of a greater number of Cabir variants going forward. To date, some seven distinct sub-species of the worm have been discovered. Most recently, the worm was found within a version of the Skulls Trojan.

Cabir, which spreads between mobile phones using a special Symbian operating system file, causes more irritation than harm, but marks the dawn of the mobile phone virus moving from mere concept into actual threat.