VirtualBox is not currently allowed to access USB devices. You can change this by adding your user to the 'vboxusers' group. Please see the user manual for a more detailed explanation.” to fix this you must add yourself to the vboxusers group.
To fix that error follow these steps:
1: Enter this into the terminal, gpasswd -a 'yourusername' vboxusers
2: Logout of your account then log back in.
3: Open up VirtualBox and USB support should be enable. Sellect the USB drive like you would on Windows.