My office computer runs Windows 2000. On occasion, I will need to leave it on when I am not in my office (or even overnight) because I expect a fax. One of our IT guys expressed a concern that since I have a modem there is the possibility of a security hole if I leave the computer on. If this is so, is there a way that I can log off the network and still leave my computer on? I have not been able to do that by simply logging off. When I log off, the computer requires that I log back on to the network to get back into Windows.
Depending on the fax software you use, you might be able to log off from the operating system and still be able to receive faxes. Many fax server software programs operate as a Windows 2000 service. That is, they run in the background even if the user is logged off. Nevertheless, this still can create a potential vulnerability. It could be possible that an attacker can gain access using the modem/fax connection. If this machine is connected to the network, then the attacker, once they have access to this machine, could perhaps access other critical machines on your network.
One solution would be to make sure that the computer you use does not have access (or at least restricted access) to the rest of the network. Better yet, it might be a better idea to purchase a separate fax machine.