Tuesday, November 23, 2004

Mobile trojans

With the arrival of the the so called smart phones the software market for mobile devices is starting to resemble the MS Windows market, in more ways than one. Unfortunately one of these ways is the appearance of viruses and malware on the new platforms. The problem seems especially severe for the Series 60 platform, due to it's use by the major handset manufacturers like Nokia and Sony Ericsson, it's acheived an near ubiquity in the smart phone market.

While I'm going to keep clear of the overused term virus, trojans are starting to appear. While they aren't in general self-replicating, worryingly some of them do display worm like properties.

The BBC is reporting the latest trojan on the Series 60 platform, while they're (at the moment) reporting it as a Nokia 7610 problem I don't see why it would not be able to infect other phones based on the Series 60 platform.

Copyright © 2004 F-Secure Corporation
The screen from a Nokia 7610 infected with SymbOS/Skulls. If this happens to your phone it's important not to reboot the phone. This will overwrite the Symbian ROM images with the malicious code and complicate disinfection. Follow the disinfection proceedures before rebooting.

On the face of things the new malware doesn't seem too worrying, until you sit down and have a serious think about things.

The combination of a piece of malware which sends illicit text messages, in a similar manner to the SymbOS/Mquito trojan, with one which propogates using the bluetooth functionality of your phone, similar to SymbOS/Cabir.A or SymbOS/Cabir.B is a troubling thought. It's especially troubling considering the security flaws which seem to be inherent in the Bluetooth protocol. If a flaw is found that lets the malware propogate without user intervention, like a true virus or worm, then there could be a some very large phone bills landing on people's door mats.

This is the dark side of the peer-to-peer messaging concept I discussed in an earlier post. The world is flat, it can be a curse as well as a blessing it seems...