Worm turns on Symbian mobile phones

A newly developed worm that affects both Symbian mobile phones and Windows systems is being investigated by security experts.

The Lasco worm is based on the same code as Cabir, the first mobile phone virus, but is the first to target Symbian Installation System (SIS) files. Once on a phone it infects SIS file systems, and a separate Windows application also looks for SIS archives and tries to infect them.

"Last year saw the start of threats aimed at mobile devices. This new threat picks up where they left off," said David Emm, senior technology consultant at Kaspersky Labs.

"The growing number and sophistication of these devices will almost certainly continue to attract malicious code writers."

Infected phones will try and spread the worm via Bluetooth and will transmit the code to the first device available in its broadcast radius.

The inclusion of code targeting Windows indicates that virus writers are responding to the increasing integration of Bluetooth in laptops and PCs.

Analysis is still going on but it looks unlikely that the worm carries a harmful payload. However, battery life may be affected as the worm searches constantly for other Bluetooth devices, Kaspersky warned.