Free Public WiFi - the wirus SSID that went round the world

So you're out and about, time to upload some photos, check for a hotspot

Hooray, Free Public WiFi.

Everywhere you go - airports, coffee shops, even right now sitting at my desk at work - Free Public WiFi.

Which would be great, except it doesn't work.

It is a profoundly peculiar interaction of human behaviour and a Windows bug.  Not helped by systems and people who can't distinguish between infrastructure networks (which commonly connect you to the Internet) and ad-hoc networks (which are for a small group of computers to quickly communicate with each other).  Of course, some interfaces, like my N82 above, don't distinguish between the two wireless network types at all.

It looks like the world's greatest social engineering hack - create a wireless virus (a "wirus", if you will) that puts up a network name (an SSID) called Free Public WiFi, and then cheerfully compromise any machine that attaches, and continue to propagate.

In fact, it turns out just to be a bug.  The short answer is, Windows does something stupid.  The long answer is, Windows will present an SSID (with no intervention from the users) of networks it has previously seen in ad-hoc mode.

It's relatively harmless for now (but don't connect to it).

See more info at

Pogue's Posts - Free Public WiFi - January 29, 2008

and a reasonably clear explanation of it (and how to avoid connecting to ad-hoc networks) at

WLAN Book - “Free Public WiFi” SSID - July 16, 2007

If you want the most technical explanation, read this advisory, which dates back to January 2006

Nomad Mobile Research Centre A D V I S O R Y - 14Jan2006
Microsoft Windows Silent Adhoc Network Advertisement
Severity : High (albeit lame)

Sidebar 1: Posting prompted by a Tweet from Paul Walk about seeing this SSID on the train, and re-prompted by it coming up when I discovered WLAN scanning was running on my Nokia N82 while I was at my desk.

Re-found Tweet through

http://twitter.summize.com/search?q=%22free+public+wifi%22

which shows this problem continues to circulate daily.  Owen Stephens provided a quick pointer in response to Paul's query.

Sidebar 2: Shiny screen + trying to take a photo of one (quick to power down to black screen) cellphone with another (quick to power down to inactivity) cellphone was quite a challenge.  This shiny screen everywhere trend wreaks havoc on taking photos, unless you want to mirrorshot yourself every time.