Well I was surprised as well and it almost sounds like science fiction but it was accomplished by the Israeli researchers as I mentioned. They are some of the best in the world . I'm sure you have heard of the Stuxnet Worm . That was the Israelis .
Covert Data Exfiltration Malware can leak data using side channels like electromagnetic signals from cables (e.g., SATAn via SATA), sound waves from speakers or fans, or even thermal emissions. Quantum scanners might detect power signatures of hidden air-gapped servers.