Trojan:SymbOS/Fontal.D is distributed in a malicious SIS file named 'Nokia Anti-Virus.sis'. On execution, it installs a corrupted Font file onto the device, causing it to fail to start at the next reboot.
F-Secure Mobile Security will detect Fontal.D and delete the trojan's components.
- 1. Open web browser on the phone
- 2. Go to http://mobile.f-secure.com
- 3. Select link "Download F-Secure Mobile Anti-Virus" and then select phone model
- 4. Download the file and select open after download
- 5. Install F-Secure Mobile Anti-Virus
- 6. Go to applications menu and start Anti-Virus
- 7. Activate Anti-Virus and scan all files
More information on scanning and removal options available in your F-Secure product can be found in the Help Center.
You may also refer to the Knowledge Base on the F-Secure Community site for more assistance.
After disinfecting the phone, remove the remaining empty directories by going to the Application Manager and uninstalling the SIS file in which Fontal.B arrived (Nokia Anti-Virus.sis).
Disinfection for cases where phone is already rebooted and cannot start up
CAUTION! This method will remove all data on the device, including calendar and phone numbers.
- 1. Power off the phone
- 2. Hold following three buttons down "answer call" + "*" + "3"
- 3. Keep holding the buttons and power on the phone
- 4. Depending on the model, you either get text "formatting" or startup dialog that asks for initial phone settings
- 5. Your phone is now formatted and can be used again
Fontal.D also drops Worm:SymbOS/Commwarrior.B and another copy of itself onto the device.
If a phone is infected with Fontal.D, it must not be rebooted as the trojan will prevent the phone from booting again.
If the phone is rebooted, it will try to boot, but will be forever stuck on phone startup and cannot be used without reformatting the phone.