The first computer virus that spreads like a real airborne contagion has been created by researchers at the University of Liverpool's School of Electrical Engineering, Electronics and Computer Science. Chameleon can spread through densely populated areas like the common cold, the researchers claim, by hopping from network to network via access points, spreading rapidly amongst homes and businesses, CNET reports.

If that weren't bad enough, the virus can avoid detection and identify weak wireless access points — those that are least protected by encryption and passwords.

"Wi-Fi connections are increasingly a target for computer hackers because of well-documented security vulnerabilities, which make it difficult to detect and defend against a virus," said Alan Marshall, Professor of Network Security. "It was assumed, however, that it wasn't possible to develop a virus that could attack Wi-Fi networks; but we demonstrated that this is possible and that it can spread quickly. We are now able to use the data generated from this study to develop a new technique to identify when an attack is likely."

The team simulated an attack on Belfast and London in a laboratory setting, and found that Chameleon behaved like an airborne virus, travelling across Wi-Fi networks via access points. It was able to remain hidden because current antivirus programs look for viruses on the internet and in computers, and Chameleon stayed on the Wi-Fi network, moving past protected access points to find those that weren't password-protected, such as public Wi-Fi access points at airports and coffee shops.

"When Chameleon attacked an AP it didn't affect how it worked, but was able to collect and report the credentials of all other Wi-Fi users who connected to it," Professor Marshall commented. "The virus then sought out other Wi-Fi APs that it could connect to and infect."

The good news is that the virus was effectively blocked by secure networks, which can be set up pretty easily, CNET says.