As described by F-Secure, CommWarrior is a worm that operates on Symbian Series 60 devices like several Nokia cellphone lines. Phones infected with CommWarrior will start searching for other devices within Bluetooth wireless range and will attempt to send infected SIS files to the discovered devices. CommWarrior will also spread via MMS as it will read the user's local address book for phone numbers and will then start sending MMS messages automatically.
I know that there are already plenty of tutorials available on the web on how to remove the said virus, but I would like to write my own version. I’m doing this because I believe that CommWarrior is still pretty much rampant. Just yesterday, my mother’s Nokia N70 got infected. It would have been costly if I did not know how to disinfect her phone because she would have to send it for repair.
F-Secure listed several CommWarrior variants with corresponding detailed descriptions. They have also given several instructions on how to remove them. So, my tips are basically just in addition to those specified by F-secure.
Case 1: If your phone can still be properly turned on, does not hang or freeze, and doesn’t restart/reboot on its own, the best thing to do is download the F- Secure Mobile Anti-Virus and follow the instructions on installation and virus removal.
Case 2: If your phone can’t be properly turned on, keeps restarting on its own, hangs or freezes occasionally, there's no other way to fix it but to "reformat" the phone or do a hard reset. A reformat will wipe out all your saved files from the phone's own memory. To do this:
a. If available, remove the MultiMediaCard (MMC) first. Then, turn the phone off.
b. Turn it on and then immediately hold the green * 3 buttons at the same time . Hold until you will be prompted to reformat, or in other cases until the "Country Select" screen will appear.
c. After reformatting, you can now install the Anti-Virus.
d. Reboot the phone and then activate the Anti-Virus.
e. Reinsert the possibly infected MMC. Run the Anti-Virus and let it clean the phone as well as the MMC. Though, I still think that the best way to clean the MMC is to reformat it.
CommWarrior or just about any other phone viruses are very easy to avoid. Just follow these simple rules:
1. Don’t leave your Bluetooth device "always on".
2. Don’t install applications that came from unknown sources.
3. Don’t download and install applications from "untrusted" websites.
That’s about it. I will leave you with some words of wisdom from the Department of Health :-)
When dealing with computer and phone viruses, or in worst case HIV virus, remember that "prevention is always the best cure".