Singlejump.G (renamed Onehop.G) is Symbian SIS file trojan that replaces system files and many 3rd party applications with corrupted binaries from SymbOS/Doomboot.A and SymbOS/Bootton.A torjans. These components prevent phone from rebooting, so if your phone is infected with Singlejump.G, it is critical not to reboot the phone or click any changed icons. Singlejump.G sends also SymbOS/Doomboot.A to the first device it finds with Bluetooth.

Disinfection with two Series 60 phones

For full disinfection of Singlejump.G you need help of another Series 60 phone that is not infected with the trojan, and clean memory card on that phone.

Download F-Skulls tool from or directly with phone

  • Install F-Skulls.sis into clean phones memory card with a clean phone
  • Put the memory card with F-Skulls into infected phone
  • Start up the infected phone. The application menu should work now
  • Go to application manager and uninstall the SIS file in which you installed the skulls variant
  • Download and install F-Secure Mobile Anti-Virus to remove any Cabir variants from or with mobile from
  • Insert the infected memory card into the phone and remove installed files

Disinfection for cases when phone is already rebooted and cannot start up

CAUTION This method will remove all data on the device, including calendar and phone numbers.

  • Power off the phone
  • Hold following three buttons down "answer call" + "*" + "3"
  • Keep holding the buttons and power on the phone
  • Depending on the model, you either get text "formatting" or start-up dialog that asks for initial phone settings
  • Your phone is now formatted and can be used again

Suspect a file is incorrectly detected (a False Positive)?

A False Positive is when a file is incorrectly detected as harmful, usually because its code or behavior resembles known harmful programs. A False Positive will usually be fixed in a subsequent database update without any action needed on your part. If you wish, you may also:

  • Check for the latest database updates

    First check if your F-Secure security program is using the latest detection database updates, then try scanning the file again.

  • Submit a sample

    After checking, if you still believe the file is incorrectly detected, you can submit a sample of it for re-analysis.

    NOTE If the file was moved to quarantine, you need to collect the file from quarantine before you can submit it.

  • Exclude a file from further scanning

    If you are certain that the file is safe and want to continue using it, you can exclude it from further scanning by the F-Secure security product.

    Note You need administrative rights to change the settings.

For more Support

Knowledge Base

Find the latest advice in our Community Knowledge Base.

User Guide

See the user guide for your product on the Help Center.

Contact Support

Chat with or call an expert for help.

Submit a sample

Submit a file or URL for further analysis.

Technical Details

Installation to system

When installed Singlejump.G will replace most common third party file managers and application installer with non-functional versions. Some icons are also replaced with application that causes device reboot.


Singlejump.G replaces built in and third party applications with component that causes reboot to fail.

Some application icons are replaced with different icons and point to application that will reboot the phone when executed.

Singlejump.G use modified Cabir to spread other trojans. Instead of sending a copy of itself it loads SIS file installed by Singlejump.G and sends it to the first phone it finds within Bluetooth range. In most cases these trojans doesn't send themselves further.