Installation instructions:

Setup for the organizers
The attached ‘challenge_6’ VM needs to be imported into the virtualization environment, the VM’s will gain IP address from the network, they have no pre-set IPs. Players need to be able to connect to the defined subnet

Setup for the players 
After installing and starting VirtualBox they can access the VM from their network (bridge, NAT, NAT network, host only). The VMs have no pre-set IPs.