Microsoft's Wireless Keyboard Hacked

Researchers crack encryption, 'own' 27MHz keyboards

December 6, 2007

3 Min Read
Microsoft's Wireless Keyboard Hacked

European researchers have hacked the 27Mhz radio-based wireless keyboard.

Max Moser and Phil Schrodel, researchers with Swiss-based Dreamlab Technologies Ltd. and , have written a proof-of-concept for capturing and decrypting keystrokes from Microsoft Corp. (Nasdaq: MSFT)'s wireless keyboards. The POC lets an attacker capture confidential data as the victim inputs it.

"The attacker can listen to all affected Microsoft 27Mhz keyboards in range at the same time. Imagining what data he could collect is a bit harder -- that depends on the person using the keyboard," says Moser, senior security specialist with Dreamlab Technologies.

But the next phase of the hack -- in which the attacker could take full control of your keyboard -- may make you afraid to ever leave your desk: "What is much badder is that we are close to the simplification of injecting our own keystrokes into victims' keyboards. [This] is already working, but not that we can show publicly [yet]," he says.

"Using that technique, an attacker could wait till you go to the coffee machine and send your keyboard a sequence of commands that opens a bad Website and installs malware, or use the old 'debug' application to [put] malware directly on your keyboard and execute it," Moser warns.

Moser and Schrodel cracked the encryption key in the Microsoft Wireless Optical Desktop 1000/2000 keyboards, but the researchers say they expect similar weaknesses in Logitech Ltd. 's 27Mhz keyboards, although they haven't yet tested them fully. The pair used a radio receiver, sound card, wires, a Linux-based laptop, and some custom software to tap and decode the radio frequencies between the Microsoft keyboard and a notebook computer.

Breaking the simple encryption on the device was easy, Moser says. "The valid encryption key is transparent during the pairing process, which gives us the possibility to listen to the keyboard without even cracking the key because we have it," he says. "And the encryption uses only one byte of random data, which allows only 256 possible combinations, which is therefore very easy to attack."

The 27Mhz keyboards are actually less secure than Bluetooth ones, which researchers already have cracked, Moser says. "They [27MHz keyboards] use much weaker encryption and the key-handling is extremely unsafe, so they are less secure than Bluetooth keyboards," he says. "But they also have an advantage -- they use completely proprietary communication protocols, so the biggest challenge is to find the important information and understand the format of data," but that isn't especially difficult, he says.

The researchers were able to eavesdrop on keyboards from a distance of up to 10 meters, through walls and floors, with a very basic copper wire antenna. "With a directional antenna, you can get much more" distance," Moser says.

They have notified Microsoft about the hack, and have no plans to release the POC for now.

"This [hack] is significant -- I have seen companies buying the 'security' in this type of equipment," says Thierry Zoller, security engineer with nruns AG. And although wireless equipment tends to be banned in security-sensitive areas, he says, employees still bring in these devices from home.

For now, you're more secure if you use a Bluetooth-based keyboard rather than a 27Mhz one, Moser says. That's because decrypting Bluetooth isn't as simple. The safest bet: a wired keyboard, he says.

— Kelly Jackson Higgins, Senior Editor, Dark Reading

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