I find it very strange that a computer can boot up with some ports open, that's beyond stupid. Nevertheless all my modems have had the default config to block a

I find it very strange that a computer can boot up with some ports open, that's beyond stupid. Nevertheless all my modems have had the default config to block all incoming requests. Imagine a port open connected to a program with admin priviles which sole purpose is to give people full access to your computer and your desktop. Hidden in plain sight, maybe?