A few suggestions...

1. 48V phantom is for condenser mic, dynamic mic (capacitive) does not need 48V.
2. In general, you should turn off 48V phantom.  However, having it on will not effect the operation of your dynamic mic.  However, 48V can damanage older microphones.  I suggest that you turn off 48V unless you know for sure that you are using condenser microphone which requires 48V DC on the line.
3. I think Audiobox itself is an interface, as such, it has DAC/ADC built in, there is no sound card involved.  Please ignore all posts related to sound card compatibility. 
4. XLR cable (3-pin big round metal plug) is balanced and will eject environment interferance by design.  However, you should check your XLR cable is of good quality and correct wiring.  If you are using TRS type (bigger version of your headphone plug), please make sure the TRS is wired in balance mode and your interface (Audiobox) supports microphone feeds in balanced TRS plug.  The interface may took TRS plug and treat it as instrument feed (guitar in high capacitance mode--high Z).
5. Your microphone may have a grounding issue.  Try to leave the microphone on a book and see if the humming goes away when you are not touching it.  

Sounds like that you are recording just fine with 48V turned off.  You are doing it correctly and you should not have turned on 48V phantom to begin with.