Security researchers on Friday unveiled an open-source device that captures the traffic of a wide variety of wireless devices, including keyboards, medical devices, and remote controls.
Keykeriki version 2 captures the entire data stream sent between wireless devices using a popular series of chips made by Norway-based Nordic Semiconductor. That includes the device addresses and the raw payload being sent between them. The open-source package was developed by researchers of Switzerland-based Dreamlab Technologies and includes complete software, firmware, and schematics for building the $100 sniffer.
Keykeriki not only allows researchers or attackers to capture the entire layer 2 frames, it also allows them to send their own unauthorized payloads. That means devices that don't encrypt communications - or don't encrypt them properly - can be forced to cough up sensitive communications or be forced to execute rogue commands.
At the CanSecWest conference in Vancouver, Dreamlab Senior Security Expert Thorsten Schroder demonstrated how Keykeriki could be used to attack wireless keyboards sold by Microsoft. The exploit worked because communications in the devices are protected by a weak form of encryption known as xor, which is trivial to break. As a result, he was able to intercept keyboard strokes as they were typed and to remotely send input that executed commands on the attached computer.
"Microsoft made it easy for us because they used their own proprietary crypto," Schroder said. "Xor is not a very proper way to secure data."
Even when devices employ strong cryptography, Schroder said Keykeriki may still be able to remotely send unauthorized commands using a technique known as a replay attack, in which commands sent previously are recorded and then sent again.
The device can also be used to spot weaknesses in cryptographic communications by comparing keystrokes to corresponding ciphertext. His analysis shows wireless keyboards made by Logitech most likely use 128-bit AES encryption. But even so, it may still be possible to decipher the contents by exploiting the way the secret key is exchanged.
"We still didn't figure out how to crack that one, but I think it's just a matter of time," he said. Keykeriki, which is the German equivalent of "cock-a-doodle-do," is available here. ®