"Most people typically go out and buy a router from Best Buy, throw it in there and call it a network," said Derek Krein, a wireless security expert. "It's pretty scary."

Krein, who is the chief technology officer with Advanced Wireless Networks in Virginia, says the assumption that home office networks are not common targets for criminals is dangerous.

"People think: 'I'm at home, no one is going to bother my home network,'" he said. "But by configuring the security properly, you make it difficult enough that criminals go elsewhere to find lower hanging fruit." (See also: )

Krein's checklist for security layers includes: a network firewall and good , kept up-to-date.

He also recommends that those who have several computers in the home put a personal firewall on any laptop they are using to further protect it from infections that may have gotten into other computers in the home network. If your laptop has Windows XP, it comes with a personal firewall; all you have to do is enable it. Windows Vista has a firewall that is turned on by default. But if you're not working with a system that already has a personal firewall, software is available from most major security-software vendors.