What is kitkat_hack MP3 file on my device?

Hello MapFactor Navigator gurus,

I have a Samsung Galaxy Note 4 running Android 5.1.1 and have recently noticed a file called kitkat_hack.mp3 on my device.  This is inside of ../data/com.mapfactor.navigator/files/...

Please could you let me know if this is a valid file (and, if so, what is it?) or have I inadvertently downloaded something dodgy? 

Thanks,

Adele