A few years ago, “borrowing” bandwidth from unprotected WiFi networks was trivial. You just cruised densely populated areas with your laptop until you came within range of an unprotected WAP (Wireless Access Point), you connected to it, and voila! Internet. I wouldn’t even call that hacking. With more and more WAP’s being protected by passwords these days, more and more people are finding it necessary to hack into wireless local nets (WLAN)s. Their use of the network might be innocent. Most WiFi password hack just want to borrow a little bandwidth to check their email or something. But a small percentage of them have nefarious purposes.
The most dangerous places to use WiFi are public networks such as in airports, hotels, or coffee shops. Even if they are passworded, realize that the same password is given to everyone, and that sometimes professional Wifi hackers hang out on these networks just waiting and sniffing. The security between computers on such a network is about the same as within a corporate network — It may have a firewall on the outside that would stop a charging moose, but once you are inside, it’s all soft and squishy. When you are on such a public WiFi network, your shared resources may be available to anyone who cares to look around at his or her network neighbors. So should you not use these networks? No, it is OK to use them, but it might be a good idea to have your sensitive stuff on a flash drive that you remove while connected to the internet. Removing your flash drive will protect stored data, but you must also be vigilant of sensitive data you transmit over the wire, such as emails, or bank account credentials. Emailing your spouse your flight info is probably OK. Emailing your company’s strategic forecast from an airport is probably not such a good idea.
With a home WLAN, you may feel somewhat protected by obscurity and geography. All the locals know about hotels, coffee shops, and airports, but they will take longer to find individual WAPs. If you live in a relatively unpopulated area and your WAP coverage area is small, you could probably look out your window and see the hacker. He has to be physically close enough to be in range. But if you live in a densely populated apartment complex, the odds of someone being close enough to hack you are much higher.
So you’ve been a diligent little internet user and passworded the access to your WAP. You don’t give that password to anyone except your family, right? Sorry, you’re still can’t totally let your guard down. If one of your neighbors has an unprotected one, the hackers will probably glom on to it, as hackers, like everyone, go for the low hanging fruit. But if all the WAPS in your area are passworded, then anyone in the area who needs access will be compelled to hack some WLAN and it might be yours. From the innocent traveler who just wants to pinch an inch of your bandwidth to the hard core evildoer who wants to zombify your computer, more and more people are hacking into WLANs. Although it does require some serious skill, that skill and knowledge has been coded and automated into hacking tools that are freely downloadable. It can be done pretty easily by anyone with minimal skill who possesses a laptop with a strong enough antenna to pick up your signal. Your firewall and your antivirus programs will not protect you from wireless sniffing. AV’s designed to look for certain types of files installed on your computer, and someone who gets on your WLAN is already inside your firewall.
My main concern with WiFi is online banking, Even though those connections are also encrypted with SSL, banks are such fat targets all hackerdom is gunning for them. I try to keep online banking to a minimum to begin with. It doesn’t hurt anyone to pack up and go to the bank once in a while. When I must do online banking, I make sure to do it from a good old fashioned wired workstation.