Behave Like You’re in Public

People generally like privacy, and hiding behind a laptop helps us forget that we’re surrounded by strangers. However, it’s important to remember that you’re sharing an Internet connection with other people. Think of it as though you are making a phone call in public. If you wouldn’t say something personal and private with people listening, don’t say it with your laptop, tablet or smartphone. Would you give a stranger your credit card or banking information? Don’t do it in a public network. Even if there’s a WiFi password, public WiFi can’t keep other laptops from eavesdropping on your communication.

Bathrobe and slippers are fine for home, but you have to get dressed to go out in public. For your computer, that means making sure your laptop has a firewall and antivirus software and that you have updated your security signatures on your home or office network before going out. It won’t protect you from every attack, but it will help protect you from automated worms and viruses that use the intimate nature of public WiFi to spread locally from computer to computer.

WiFi has become so common that almost anyone can set up a hotspot. Many smartphones also have built-in hotspots. One of the easiest ways to attack a computer is to pretend to be a hotspot and wait for people to connect. If there’s any confusion about which network to connect to, stop what you’re doing and ask someone who works there. This is especially true if the “free” WiFi asks you for a credit card to get online. It’s an easy way for an attacker to steal that information from you.

If you’re going to do some work, the first thing you should do once you’re connected to the WiFi network is to connect to your company’s VPN. A VPN encrypts all traffic in a way that hides your data and hides the identity of the servers to which you are connected. Although the behavior of VPNs can vary, most of them will also prevent your computer from talking to any computers on the same public WiFi network.

Even if you’re not going to do work, the benefits of using a VPN are strong enough that you should use your company’s VPN any time you are using public WiFi. If your VPN protects your laptop from other computers on the public WiFi, it gives you much stronger protection against worms and viruses that like to leap from computer to computer. Your company IT staff may prefer that you use the VPN for nonbusiness traffic, rather than bring a virus into the office.

Most people know this by now, but an encrypted Web page gives you better protection than a nonencrypted Web page. It’s not as safe as a VPN, but it’s better than nothing. Just remember that there are ways for the “bad guys” to try to confuse your browser, and show you a fake Website that looks like a real one. While this problem isn’t isolated to public WiFi, it’s an environment that makes it easier to lead your browser astray.

Part of the power of computers in an office is their ability to interconnect and that turns into a big weakness in a public environment. Microsoft added Network Location Awareness to Windows Firewall in Vista, which means that when you connect to a network, Windows will ask you whether it’s work, home or public. While choosing “public” should stop most information leaking from your PC to everyone around you, be aware that you may also have other programs running that like to share your MP3 library, home movies, tax returns and so on.

Public WiFi varies a lot by location. Some networks are fast, and some are so overloaded that it’s hard to get online at all. It’s tempting to try to make the connection faster by turning off antivirus. That’s like trying to drive faster on a bumpy road by disconnecting the brakes. Not only will it not speed up your download, it makes you much less safe in the worst possible place.

Remember when using public WiFi that you’re not just on the Internet, you’re on a network with a bunch of strange computers, some of which have viruses, and some of which may be specifically trying to attack you. If anything looks out of place, such as warnings about Website certificates, log-in fields in a different location, unexpected requests for personal information or credit card numbers, stop what you’re doing and put your computer away. It’s probably not anything to worry about, but a little paranoia now can save you a lot of problems later.

After using a public WiFi network, it’s always a good idea to check the health of your computer. Even if you were using the network at a local business you trust, you can’t guarantee that there wasn’t someone else on the same network who is less careful than you. Pull out your laptop and run a malware scanner. If possible, do it once before you connect to your home network and then once again after you update your signatures.