Hard disks can be turned into listening devices

Eggheads at the University of Michigan in the US, and Zhejiang University in China, have found that hard disk drives (HDDs) can be turned into listening devices, using malicious firmware and signal processing calculations. “Our research demonstrates that the mechanical components in magnetic hard disk drives behave as microphones with sufficient precision to extract and parse human speech,” their paper, obtained by The Register ahead of its formal publication, stated. The offset is referred to as the Positional Error Signal (PES) and hard drives monitor this signal to keep the read/write head in the optimal position for reading and writing data.

Source: www.theregister.co.uk