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Ars: Cross-Platform Malware Communicates With Sound
An anonymous reader writes "Do you think an airgap can protect your computer? Maybe not. According to this story at Ars Technica, security consultant Dragos Ruiu is battling malware that communicates with infected computers using computer microphones and speakers." That sounds nuts, but it is a time-tested method of data transfer, after all.
Back when I had an altair 8800 we used to play a teletype game called star trek. We kept a radio tuned off channel on in the room. When you fired a laser the code executed a fast loop that emitted EMI in a ramping frequency. the radio would make a phaser noise.
IN Europe it was discovered that the most common brand of voting machine would emit EMI differently depending on whether the character in the displayed name had an umlat or not (special character set). SO you could tell who people voted for when one candidate had an umlat.
Some drink at the fountain of knowledge. Others just gargle.
Besides the many, many stretches of the imagination required for his story (e.g., it infects the firmware on all major brands of USB drives, he never extracted a binary blob or sent the infected device to the manufacturer, the audio communication silliness, the fact that he apparently thinks infection could spread through the power cable, and so on...) the biggest issue to my mind is that if this is so communicable, why in all the time he's had it under observation has it never spread anywhere else? Also, why has he not shown it to a colleague. This is the sort of thing that goes over huge at conferences.
Assuming this is more than a hoax, here's a bit of devil's advocate:
After the initial infection and subsequent cleaning (let's assume it survived somehow - hell, it might have been a compromised USB keyboard), the issue was forgotten for a while until the mentioned symptoms started appearing - since they seemed to be mostly inconveniences that often plague BIOS/UEFI (If I had a buck for each hour I've spent figuring out how to boot with drive X on system Y...) or could be atributed to more mundane causes, the investigation of these issues was considered not prioritary, as there were seemingly more important tasks to do.
More recently, a connection was established that suggested it might be more than just random bad luck - this then took a while to investigate, especially because ruining hardware (desoldering the BIOS chip to extract its firmware) is typically the last resort when investigating something.
Again, this is just speculation as to why this whole story took three years so far.
And regarding the power cable: Powerline networking is commercially available and well-understood, as is transmitting data along with low-voltage DC (PoE). If you come to the conclusion that information is being exchanged after removing all network interfaces, it makes perfect sense to try (it's not exactly hard...) to unplug the laptop, to eliminate a potential hardware backdoor. Honestly, what I considered paranoia not too long ago is starting to look more likely every day...