"Malware Lets a Drone Steal Data by Watching a Computer’s Blinking LED"

Researchers at Ben-Gurion’s cybersecurity lab have discovered ways in which drones can steal data by scanning a computer’s LED indicator light. This hacking technique manages to bypass “air gap”, a security method designed to separate computers from the internet in order to be untouchable by hackers.  This article discusses how the hard drive indicator LED light can be exploited for information leakage as well as how this hack is performed.

https://www.wired.com/2017/02/malware-sends-stolen-data-drone-just-pcs-blinking-led/