If you're trying to run Remnux on KVM by loading the OVA:
To get network access: KVM changes the network adapter name, so you've got to change the config in /etc/netplan, replacing the old vmware adapter (like enss0) with whatever the new one is and then reboot. You can use networkctl to find the non-loopback adapter name (like en1ps0)
The Remnux docs also say to run "remnux install" after loading into KVM to install spice and other tools. When I do that, it makes the VM worse: cursor disappears, resolution gets jacked.
Instead, installing spice-vdagent using apt gets you all the nice stuff like dynamic resolution and copy-paste. Afterwards, if you try to use remnux-install, it will again break the vm tools inside the VM. I'm unsure the cause.
✅🎯🙄