Why do people go crazy when the firewall if off? Most sites on the internet say its very dangerous to turn off your firewall and I want to understand why. For example Microsoft says this:
You should always run Windows Firewall even if you have another firewall turned on. Turning off Windows Firewall might make your device (and your network, if you have one) more vulnerable to unauthorized access.
Now I want to understand how does it make my infrastructure vulnerable. If you have malware already on your computer and then you turn off the firewall then yes I understand that then the malware will be able to send and receive Command-and-Control traffic.
But if a computer with a fresh installation of Windows has its firewall off then how would you hack it? You will be able to send all the packets you want to that computer but that computer will not know what to do with those packets right?
It will be great if someone gives an example/describe of how to hack a computer that has no firewall and has a fresh installation of Windows (remote desktop connection is disabled and a username and password is needed to login into that computer).