Well, this is an open question.
Are the machines fully patched? Do they run antivirus? Do you have a firewall in place? That stops a good number of attacks.
But then have you got security hardening applied? Is there potentially a new exploit or unknown vulnerability?
You wouldn’t willingly let an attacker into your network would you? So don’t allow your machines to connect to compromised or potentially compromised networks.
I feel this conversation is irrelevant now as you clearly have no understanding whatsoever of real world security.