Once installed, Locknut will prevent any application on the infected device from being launched.  Some versions of Locknut also drop Cabir onto the device,  however in this instance, the Cabir virus is harmless since Locknut effectively prevents all applications (which includes Cabir) from launching.  If Locknut is removed, the dropped Cabir virus will still not start due to being dropped into the wrong directory.  However if the user manually starts Cabir, it will become active.

Locknut is targeted primarily toward Symbian Series 60 devices but Series 70 devices such as Nokia 7710 are also vulnerable.