Trojan:SymbOS/Blankfont.C

Classification

Blankfont.C

Summary

Trojan:SymbOS/Blankfont.C is a SIS file trojan that installs corrupted system binaries/font file. The system files dropped by Blankfont.C cause the device to fail on the next reboot. If you have installed Blankfont.C, the most important thing is not to reboot the phone and follow the disinfection instructions in this description.

Removal

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 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.

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 file installed to the phone does not cause device to crash, but if the device is rebooted it will then lose the system font and is unable to display user interface texts.

Installation to the System

Blankfont.C installs corrupted system binaries into the C:\ drive of the phone. When the phone boots these corrupted binaries will be loaded instead of the correct ones, and the phone will crash at boot.