Just as technology is advancing, Cybercriminals and hackers are also becoming masters in their act. Researches have been made and it was discovered that hackers, can quietly steal important information from air-gapped computers by manipulating the of their screen by just 3%.
This was discovered by researchers in the Isreal’s Ben-Gurion University of the Negev and the Shamoon College of Engineering.
They also revealed how a piece of malware could extract valuable data from a device.
For example Passwords, Encryption keys, files modulate it in screen brightness and transmit it to the nearby camera.
How it works
The researchers have proposed modulating harvested data by assigning a “1” value to 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 three percent.
Therefore the changes 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.
The attack was tested using two displays – a 24″ PC monitor from Dell and a 40″ LED TV from Samsung-and three types of cameras, namely a Sony security camera, a Microsoft webcam, and the camera of a Samsung Galaxy S7 smartphone.
The security camera and the webcam performed the same. They captured data from up to 9 meters (30 feet) at a bitrate ranging between 5 to 10 bits per second. The smartphone camera only worked over distances of up to 1.5 meters (5 feet) with a bitrate of 1 bit per second.
The researchers have pointed out that the room where they conducted the experiments only allowed for a maximum distance of 9 meters between the screen and the cameras, but the attack likely works over longer distances as well.