Wednesday, March 25, 2015

Defeating air gaps using heat.

Traditionally, a computer that is off the Internet and off the local network is considered safe. This is called an air gap, there's air between the computer and all other computers. I've posted before about guys using radio frequency (RF) shenanigans to defeat the air gap.

Now there is a new idea. This one uses heat.

The proof-of-concept attack requires both systems to first be compromised with malware. And currently, the attack allows for just eight bits of data to be reliably transmitted over an hour—a rate that is sufficient for an attacker to transmit brief commands or siphon a password or secret key but not large amounts of data. It also works only if the air-gapped system is within 40 centimeters (about 15 inches) from the other computer the attackers control. But the researchers, at Ben Gurion's Cyber Security Labs, note that this latter scenario is not uncommon, because air-gapped systems often sit on desktops alongside Internet-connected ones so that workers can easily access both.

The method uses thermal sensors inside both computers to detect outside increases in heat. The malware uses the CPU to increase and decrease the temperature inside one machine, these changes are detected by the thermal sensors in the other machine. In this way they can exchange ones and zeros, one at a time, minutes apart. Slowly over the course of hours larger messages can be exchanged.

Currently the hack can be defeated just by moving one of them to the other side of the desk. But the very idea that you can transfer even small amounts of data like this is amazing. Previously it didn't matter what kind of malware your computer was infested with, if you unplugged the network you were safe from intrusion. Now, not so much.

Also to be considered is that this hack was developed by a student. Some kid whipped this up as part of a Masters or a PhD.

Imagine what the guys who do this for a living have come up with these last 25 years.

In other news the Kremlin has switched from word processing on computers to typewriters, in a back to the '50s move. So I guess they've been reading about this stuff too.

Personally I think the venerable typewriter is too hack prone, everything you type is recorded on the ribbon, don't forget. I'm going back to a pencil and paper for all my world domination plans. Inside a Faraday cage. In the cellar. Burn before reading.

The Phantom

No comments: