Locknut.B is another malicious .SIS file that pretends to be a patch for Symbian Series 60 mobile phones. It disables the phone so that it can only be disinfected with a special disinfection tool. When installed, Locknet.B crashes an important system component, preventing any program from being launched. It also copies Cabir.V to the phone, but since Locknut.B prevents it, too, from being launched, it causes no immediate harm. It was renamed from Gavno because that word is explicit in some Eastern European countries.