Security News > 2020 > February > Hackers Can Steal Data From Air-Gapped Computers Via Screen Brightness
Researchers have shown how hackers could silently exfiltrate sensitive information from air-gapped computers by manipulating the brightness of their screen.
Researchers from Ben-Gurion University previously demonstrated how hackers could exfiltrate data from air-gapped systems via power lines, magnetic fields, infrared cameras, router LEDs, scanners, HDD activity LEDs, USB devices, the noise emitted by hard drives and fans, and heat emissions.
The researchers have proposed modulating harvested data by assigning a "1" value to a certain screen brightness and a "0" value to a different brightness.
Quickly changing the screen brightness results in a sequence of bits that can be captured by a camera pointed at the screen.
While it may seem that a screen whose brightness keeps changing would attract attention, the experts determined that it's enough to change the red color of each pixel by only 3%. This small change in brightness is not visible to the naked eye, but it can be captured by a camera, which allows the exfiltration process to take place even while a user is working on the targeted computer.