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Biz travelers beware: Airport ad-hoc hot spots could be dangerous

A new study suggests that travelers who connect to free, ad-hoc wireless networks risk allowing hackers access to confidential files.

Public Wi-Fi hotspots in airports can be a lifesaver for many business travelers, but a new study released this week suggests that road warriors could be vulnerable to hack attacks if they aren't careful about which networks they connect to while waiting for their flight.

Jason Hiner, executive editor at CNET's sister site TechRepublic, wrote a blog on Wednesday about the new study published by a company called AirTight at the Gartner Mobile and Wireless Summit in Chicago on Monday. AirTight Networks, which sells wireless-intrusion-prevention software, conducted its study in 11 U.S. airports and three airports in the Asia-Pacific region between January 30 and February 8 using standard Wi-Fi cards and packet tracing software.

The company found that hackers can gain access to information on a laptop hard drive by setting up fake ad-hoc or peer-to-peer Wi-Fi networks in airports. The SSID (service set identifier), which is used to identify nearby wireless networks, appears as an icon with two laptops connecting to each other and is often named something appealing, such as "Free Public Wi-Fi" or "Free Internet!"

When a user tries to connect to one of these supposedly free wireless networks, Windows automatically adds the SSID to the preferred networks list. The vulnerability spreads as the fake SSID is automatically broadcast to other users, who then try to connect to it. These laptops then become infected.

Once someone is infected with the bogus SSID, anyone who knows of the attack can use the connection to access shared files on the infected laptop. The open wireless connection could also allow hackers to access confidential files on a laptop.

In his blog post, Hiner said that there is no payload or tricky code involved in the attack, so it's virtually impossible to track. But because the exploit essentially creates public access to a laptop, anyone who knows the laptop is infected can also exploit the vulnerability.

AirTight, the company that conducted the study, found that 10 percent of all wireless users it scanned in the airports it surveyed were broadcasting at least one bogus SSID. In some airports the percentage was higher. At the John Wayne Airport in Orange County, California, almost 22 percent of laptops were transmitting one of the viral SSIDs. About 17 percent of laptops surveyed at Fort Lauderdale Hollywood International airport in Fort Lauderdale, Fla., and Pittsburgh International Airport had one or more of the viral SSIDs.

For a full list of the SSIDs used in the attack check out Hiner's blog. He suggests that the best way to make sure you don't fall victim to an attack is to never click on an ad-hoc network, which is the icon with the two laptops. And users should stick to paid public Wi-Fi hot spots, such as ones offered by companies like Boingo.

AirTight also recommends that people connect to their corporate VPN after accessing a public Wi-Fi hotspot and before they do any corporate work. And finally, the company also recommends that IT departments implement software, such as their own, that helps detect wireless intrusion.