This post shows you a way to convert VirtualBox to vhd for Hyper-V. It does not sound nice VirtualBox actually provide an exe command to convert the VM image, vmdk, that is compatible to VMWare, to vhd for Hyper-V.
You need to install VirtualBox. For me I installed 5.2.22. Normally the default installation folder will be C:\Program Files\Oracle\VirtualBox if you have not changed it. Go to that folder and run VBoxManage.exe like the example below.
C:\Program Files\Oracle\VirtualBox>VBoxManage.exe clonehd “C:\Kali-Linux-2018.2-vbox-amd64\Kali-Linux-2018.2-vbox-amd64-disk001.vmdk” e:\temp\kali.vhd –format VHD. You can then use the image for Hyper-V.