Fascinating hack

[George K]

https://www.zdnet.com/article/academics-turn-ram-into-wifi-cards-to-steal-data-from-air-gapped-systems/

Academics from an Israeli university have published new research today detailing a technique to convert a RAM card into an impromptu wireless emitter and transmit sensitive data from inside a non-networked air-gapped computer that has no Wi-Fi card.

Named AIR-FI, the technique is the work of Mordechai Guri, the head of R&D at the Ben-Gurion University of the Negev, in Israel...

At the core of the AIR-FI technique is the fact that any electronic component generates electromagnetic waves as electric current passes through.

Since Wi-Fi signals are radio waves and radio is basically electromagnetic waves, Guri argues that malicious code planted on an air-gapped system by attackers could manipulate the electrical current inside the RAM card in order to generate electromagnetic waves with the frequency consistent with the normal Wi-Fi signal spectrum (2,400 GHz).

In his research paper, titled "AIR-FI: Generating Covert WiFi Signals from Air-Gapped Computers," Guri shows that perfectly timed read-write operations to a computer's RAM card can make the card's memory bus emit electromagnetic waves consistent with a weak Wi-Fi signal.

This signal can then be picked up by anything with a Wi-Fi antenna in the proximity of an air-gapped system, such as smartphones, laptops, IoT devices, smartwatches, and more.

Guri says he tested the technique with different air-gapped computer rigs where the Wi-Fi card was removed and was able to leak data at speeds of up to 100 b/s to devices up to several meters away.

[jon-nyc]

@george-k said in Fascinating hack:

Guri shows that perfectly timed read-write operations

It’s cool, but I wonder if the ‘perfect timing’ occurs in practice. I’m guessing not.

But that might just mean you need to build a custom receiver to pick it up at ‘native’ speeds rather than use standard WiFi frequencies.

[Copper]

I worked at a secure government location where they took this sort of thing seriously.

This was in 1983 and they were concerned that people could sit in a van across the street from the building and pick up, and read, signals from keyboards plugged into the computer terminals.

So everything in the building had to be Tempest Tested to demonstrate that these signals were stopped.