‘PIXHELL’: new method lets you steal data through computer screen noise

An innovative cyber attack method, Extracting hidden data by capturing the noise produced by the pixels of a computer’s LCD screenAccording to a study published on the platform, the technique called “PIXHELL” targets computers that are isolated from external networks (air-gapped) arXiv Saturday (7).

The attack begins with the malware being air-gapped into a computer, according to Mordechai Guri, an expert at Ben-Gurion University of the Negev in Israel. The malicious file captures specific frequencies emitted by the monitor’s coils and capacitorsUndetectable by the human ear, as shown in the video below.

These sounds, which are generated from the pixel patterns displayed on the screen, are read by the malware so that the program can collect Sensitive information typed on the machine’s keyboard, such as passwords and encryption keysconverts these into “0” and “1” bits that are transmitted through the noise of the coils and shield capacitors.

According to the head of the Offensive Cyber ​​Research Lab at an Israeli university, the acoustic signals in the PIXHELL attack are captured by a mobile phone, laptop or microphone. Although, The device should be within 2m from the screen.Data transfer occurs slowly, at a maximum rate of 20 bits per second.

Data protection

Although difficult to execute and requiring the cybercriminal to be very close to the target device to extract the data, the PIXHELL attack can cause major losses. According to Guri, air-gapped computers often store critical dataso some maintenance is needed.

The researcher suggests: application of acoustic barriers to neutralize the transmission and capture of noise emitted by the screenas well as monitoring the audio spectrum for unusual signals. Another precaution is to limit physical access to the room where the air-gapped PC is located and allow only authorized personnel to access it.

He also recommends banning smartphones in these places and using a camera to constantly monitor the monitor. look for unusual pixel patternsThis may be an indication of ongoing research.