Trojan:SymbOS/Blankfont

Classification

Malware

Trojan

SymbOS

Trojan:SymbOS/Blankfont, Trojan:SymbOS/Blankfont

Summary

Trojan:SymbOS/Blankfont is a family of SIS file trojans that install a corrupted Font file.

Manual disinfection

  • Uninstall the SIS file with which Trojan:SymbOS/Blankfont was installed
  • To make sure that uninstallation was successful, scan your phone with an antivirus program before rebooting the phone

Disinfection for cases when the phone has been rebooted

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

Trojan:SymbOS/Blankfont copies corrupted font files into the phone's memory and thus prevents the phone from loading the valid font files from ROM.

The corrupted font files installed onto the phone will not cause the device to crash, but if the device is rebooted it will then lose the system font and will be unable to display user interface texts.

Variant Descriptions