The first time I heard of this technique it was (supposedly?) used for airgapped, infected machines to communicate [0]. I don't remember, though if it was prove

The first time I heard of this technique it was (supposedly?) used for airgapped, infected machines to communicate [0]. I don't remember, though if it was proven in the end that that was actually how the malware communicated. There was some skepticism. [0] https://en.wikipedia.org/wiki/BadBIOS https://en.wikipedia.org/wiki/BadBIOS