I love wireless Internet access. When I first got a laptop, I would access any random signal I could hop onto, and off I went, surfing the Internet and chatting with friends. I have to admit I got a giddy feeling doing this, like I was getting away with something. Plus it was free. But while no one loves a bargain more than I do—I'm a fiend at a sale rack—using an unknown network can be lethal to your computer's health and your financial well-being.
How? I was recently on a train going from New York City to Connecticut, laptop in hand. For the entire two-hour trip I noticed an open network I could join called "Free Public WiFi." Sounded great. The only problem is I know Amtrak isn't yet offering Internet access on its trains. I've also seen this at airports that aren't known to offer free wireless.
So what is it? It's likely a scam set up by someone with a nearby laptop. The sneaky part of the ruse is that you can sometimes access the Internet from such a network if the scammer has set up his computer to let you surf the Web via his connection. But by using his connection, your information is being transmitted through his computer, which means he can see everything you do online, like entering your usernames and passwords for banking and other websites. The scammer may even gain complete run of your computer, stealing files and data as he pleases.
To fool us, scammers sometimes duplicate the name of a legitimate network, something the geek literati like to call an "evil twin." This means you may see two networks with the same name, but one of them is bogus and probably has a nefarious purpose.
What can you do to protect yourself?
1. Try to use only wireless networks that you know are legitimate.
2. Try to use networks that are password-protected—that is, ones that require usernames and passwords.
3. Avoid doing online banking or sending financial information when you're on an unfamiliar network. Similarly, don't send personal financial information from Internet café computers rented by the hour, library computers, or the like.
4. On a Mac, turn file sharing off on your computer and/or restrict file sharing through password protection. You'll find those options under "System Preferences" in the "Internet & Network" section. On a Windows PC, turn off the guest account. This may seem complicated, because the steps are different depending on which operating system you're using—Windows 98, XP, or Vista—so Google "turn off file sharing XP," for instance, and you'll find the procedure you need.
Lastly, all hacking isn't high-tech. "Shoulder surfers" don't need any fancy equipment to steal your password; they only need to peek over your shoulder.