Anti-virus firm F-Secure Corp. has discovered another variant of the Commwarrior worm, which attacks phones that use the Symbian Ltd. operating system.

Commwarrior.Q can be spread via text messages, Bluetooth connections, or swapping memory cards in your phone, according to Tony Magallanez, systems engineer for F-Secure. The mobile malware launches its own browser page after it infects the device, but can be disabled by the user or blocked by mobile anti-virus software, Magallanez says.

As with many current mobile viruses, this piece of malware's current potential for mayhem doesn't seem that great. "It seems to be a fairly low infection rate... probably no more than a few hundred users," says the engineer.

It is, however, the awesome potential for these viruses spreading in the future that disquiets many in the security community. (See The Blue Flu?) For instance, Kaspersky Labs earlier this year estimated that a worm for mobile devices would be able to infect nearly all vulnerable devices in Moscow within 15 days.

Commwarrior, however, cannot automatically download so has to be triggered by a user, which limits its ability to spread.

— Dan Jones, Site Editor, Unstrung