theoretical risk of malware infection

It's not that I'm really afraid of this happening (at least I don't think I need to be this paranoid yet), but I was just wondering:

With a cable modem, you're always connected to the internet, so if you're logged into Windows, then don't you not even have to open your browser to in effect be visiting your homepage, and thereby be risking malware infection?

 

Hi

That fits the description of an internet worm. It's one reason why people use firewalls. A router between your cable modem and computer will also protect you from these, and is highly recommended here.

Windows has what are called ports. Each port can pass data back and forth. Some of these ports are "open" meaning a Windows operating system program (service) is waiting on the port for a remote computer to possibly send your computer data. Worms take advantage of bugs in these services to infiltrate your computer.

A router or firewall will prevent this from happening in most circumstances, so that even if there was some vulnerability that was only known to an attacker, the worm they created would not get past the router or firewall because these essentially close the open ports.

However, if you connect to a website that has malware, that same vulnerability above could be used to attack your system, since by visiting a website with malware you essentially invite the malware in, past the router or firewall. This is one reason why you should always keep your software fully updated, so that these bugs are fixed and any malware that tries to exploit them is blocked.