According to David Maynor, chief technology officer at Errata Security, computers are “leaking all kinds of information that an attacker can use” once they connect to a Wi-Fi network, particularly in public areas such as airports. Existing tools can obtain important details like usernames and passwords for e-mail accounts and instant messengers. To address this situation, Errata announced it will release a tool called Ferret that informs users how much information they are making available to the public once their computers start searching for wireless networks and network services. The Errata sniffer, which will be released on the company’s website, can run on any wireless card. Robert Graham, the firm’s chief executive, promised to publish the sniffer’s code on the Black Hat website soon.
In the case of a Windows computer, Ferret can generate a roster of wireless networks to which the PC secured connection previously, provided the user has not taken out the entries from the preferred networks list in Windows. The Bonjour feature reveals the version of the operating system used by Apple Mac OS X computers. The sniffer also shows the past Internet Protocol address and information on networked drives or devices like printers that the computer tried to access earlier.