"Free Public Wi-Fi" is Microsoft Windows Silent Adhoc Network Advertisement crying wolf

The puzzling phenomenon of seeing "Free Public Wi-Fi" that you can't connect to when you're searching for free public wi-fi has been solved. It's "Microsoft Windows Silent Adhoc Network Advertisement."

From a Nomad Research Centre Advisory:

This advisory documents an anomaly involving Microsoft's Wireless Network Connection. If a laptop connects to an ad-hoc network it can later start beaconing the ad-hoc network's SSID as its own ad-hoc network without the laptop owner's knowledge. This can allow an attacker to attach to the laptop as a prelude to further attack.

Basically, what's going on with "Free Public Wi-Fi" is that when you connect to a network with an SSID such as "Free Public Wi-Fi," your Windows computer retains that SSID. But the glitch is that it also will broadcast this SSID inviting other computers within range to connect with your computer in an ad hoc network. The ad hoc network only allows the other computer to connect to your computer, which you most probably don't want to offer. When you're looking for a Wi-Fi connection, you're looking for an access point which will connect you to the Internet.

Of course, when other users see the "Free Public Wi-Fi," they naturally want to connect to such a fetching SSID, and voila, they've got it in their system, and they'll be broadcasting it to others eventually. In reality, no one is connecting to the Internet via this SSID, but it is still being spread in a viral fashion in the connected world of laptops.

Somewhere there is a hot spot where you can connect with the SSID "Free Public Wi-Fi" that started all this going. Who knows where?

Some enterprising marketer might use this bug to create a viral campaign using the SSID "Miller Lite beer, less filling, free public wi-fi" and spread to message to countless road warriors who then spread it throughout the Wi-Fi laptop universe.