en Passant

In recent months, I have noticed quite a few new local wireless hot-spots appeared in my neighborhood. These hots-spots are my neighbors (within 1000 feet of my house), who are using the out-of-the-box configuration and no security measures. This means anyone driving by my house can access the Internet while sitting in their car (war driving).

Using a free tool (Netstumbler), I can gather information about all my neighbor's wireless routers, including name and encryption settings.

Now that I know their router settings, I can become a member of their network. In addition to using their connection to the Internet for free, I could connect to shared network resources, like printers, and shared drives. Additionally, since they haven't enabled encryption on their router, they probably haven't changed the router's admin account password.

With little effort, I logon to their router, and check the DHCP table for a list of currently active devices, including computer names and IP addresses. I can try PINGing the IP address and see if it responds. If it responds, I can try mapping a drive to the default admin shares like C$ or browse the computer by simply typing in the IP address in the Windows START - RUN line, "\\192.168.1.100", and see what comes up. By default, Windows will have a "Shared Doc" folder available, but sometimes you will also see a printer listed here.

What can you do about it?

• Change your router's SSID. By broadcasting the default SSID assigned by the manufacturer, anyone can GOOGLE your manufacturer and determine the administrator logon and password for that model. Ouch! Now the hacker can lock you out of your own network.
• Implement WEP on your wireless devices - Configuring a WEP key is quick and easy. The hardest thing is often touching each wireless device and entering the WEP key. Just make sure your WEP key is unique and not a straight dictionary word. If your WEP key is Woodford, make sure it isn't printed on the front of your house. Of course, with as many open APs in the neighborhood a hacker will just drive next door and try there instead.
• Define MAC limits: A MAC address has nothing to do with the golden arches, but is the unique identifier assigned to each network device. The address is 12 digit hexidecimal containing part manufacturer identifier, one part pooled number. You can find your MAC address (or Physical Address) on Windows NT/2000 or XP machines by running IPConfig /All (see attached screenshot) in a command window. Input this information for each device into your router's configuration. By locking down your network to a specific set of MAC addresses, the hacker has to try to spoof the one of 281,474,976,710,656 (16^12) possible combinations.

Like security for your automobile, doing the basics of locking the doors and closing the windows is enough to deter most (wireless) thieves. They can always simply travel next door and find a much easier target. With the security now configured on your wireless router, you should be able to easily move your wireless devices between home, work and the coffee shop wireless networks with very little difficulties.