C:\Program Files\Oracle\VirtualBox>VBoxManage.exe list dhcpservers
NetworkName:    HostInterfaceNetworking-VirtualBox Host-Only Ethernet Adapter
IP:             192.168.56.100
NetworkMask:    255.255.255.0
lowerIPAddress: 192.168.56.101
upperIPAddress: 192.168.56.254
Enabled:        Yes

C:\Program Files\Oracle\VirtualBox>VBoxManage.exe dhcpserver modify --netname "HostInterfaceNetworking-VirtualBox Host-Only Ethernet Adapter" --disable

C:\Program Files\Oracle\VirtualBox>VBoxManage.exe list dhcpserve
NetworkName:    HostInterfaceNetworking-VirtualBox Host-Only Ethernet Adapter
IP:             192.168.56.100
NetworkMask:    255.255.255.0
lowerIPAddress: 192.168.56.101
upperIPAddress: 192.168.56.254
Enabled:        No