Early computer viruses spread over what we called "sneaker net," with one infected floppy disk inserted in one computer after another. Online networks make infections move much faster — but, until now, all the infections had been from computer to computer, or server to computer. They had never spread from one disconnected Wi-Fi network to another before.
Researchers at the University of Liverpool have created (in the lab only, thankfully) what may be the first computer malware that can spread like the common cold: over the air, depending on proximity between the infected host and an uninfected victim.
The malware, called "Chameleon," sits on a network and basically sniffs the data and credentials passing through it. It can hop from access point to access point, and just like a cold, moves more quickly in densely populated areas. Those places naturally have more access points offering Wi-Fi connections to the unsuspecting public. To put this in perspective, anytime you're accessing a Wi-Fi network, you're connecting to an access point — the world and Starbucks are full of them.