> Guri says that malicious code planted on an air-gapped system can control the speed at which fans work. By moderating fan speed up and down, the attacker can

> Guri says that malicious code planted on an air-gapped system can control the speed at which fans work. By moderating fan speed up and down, the attacker can control the frequency of the vibrations coming off the fan. Ah, so it's a malicious program using fan vibrations to communicate data to an attacker via sound where the attacker doesn't have a network connection to the computer the malicious program is running on? I thought it was going to be something to do with e.g. passively reading passwords/keys via the fan vibrations somehow when the system was running non-malicious code.