Why you should avoid "Free Public Wi-Fi" networks

By on October 11, 2010, 6:24 PM
Have you ever tried connecting to the Internet and a Wi-Fi network titled somewhere along the lines of "Free Public Wi-Fi" caught your eye? If you hang out in airports, libraries, coffee shops, school campuses, or laptop-friendly public places in general, chances are you've seen something of the sort. Failing to get onto the Internet via an actual Wi-Fi hotspot, you may have tried connecting to one of these, and since then you've probably never bothered. It didn't work the first time (which should be enough of a deterrent from trying it again), but you probably never bothered to find out why. The reason lies in an odd bug found in all versions of Windows XP, save for those updated to Service Pack 3.

"Free Public Wi-Fi" isn't actually free, isn't actually public, and isn't actually a Wi-Fi service, according to NPR. The issue occurs when an older version of XP can't find any of its favorite or saved wireless networks: it gives up, automatically creates an ad hoc network with the same name as the last one it connected to (for the sake of this article we're using the name "Free Public Wi-Fi"), and shows up on other computers within range. Those lured in the by the word "free" connect to it only to disconnect in frustration when they realize it's useless.

If you connect to such a network, chances are high that all you've done is connected to a computer whose owner is ignorant that he or she is broadcasting an ad-hoc network. That being said, there are always those who will purposely exploit this bug to gain access to your computer or the account credentials on it. Remember: Windows clearly shows the difference between a wireless network and a computer-to-computer network, and unless you're trying to get Internet from a friend, you'll almost always want to connect to the former.

User Comments: 8

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dustin_ds3000 dustin_ds3000, TechSpot Chancellor, said:

http://www.youtube.com/watch?v=N_tnHHEFGKs - Hak5: Airport WiFi Challenge

Darth Shiv Darth Shiv said:

Wouldn't most people have SP3 now?

Flannelwarrior said:

If I saw an ad-hoc network like that called "Free Public WiFi" I'd think only that there was a douche sitting somewhere near me preying on people who don't know how to computer.

tengeta tengeta said:

I've noticed those before and ran away the second I noticed they were ad-hoc. I could see less experienced computer users double clicking it out of frustration in not being able to find Wi-Fi though.

Lokalaskurar Lokalaskurar said:

I've never seen this "Free Public WiFi", although if I did, I'd be pretty sure to shut off the WiFi-card card and move to another location. Atleast now I know what to look out for.

Tanstar said:

Darth Shiv said:

Wouldn't most people have SP3 now?

What he said. Why wouldn't you take a free upgrade?

freythman freythman said:

This... is... old news..... This has been around for a couple years.... GIVE ME SOMETHING RELEVANT! RAWR!!!!

jobeard jobeard, TS Ambassador, said:

The Windows 7 firewall has three choices for 'type of network': Home, Work & Public.

While at a hotspot (free or otherwise), be sure to select the Public option and it will configure itself to stop access to your system for all those MS specific ports, eg: 137-139, 445

Users of other systems (XP, Vista) must learn how to configure their specific firewall product to do the same.

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