Researchers at BGU's Cyber Security Research Center (CSRC) have demonstrated for the first time that it is possible to covertly siphon sensitive files, passwords or other critical data from any common router.
In the new paper, the researchers demonstrated how LEDs functionality can be silently overridden by malware they developed (code named “xLED”), which infects firmware in the device. Once the xLED malware infects the network device, it gains full control of the LEDs that flash to indicate status.
Network devices such as routers and local area network switches typically include activity and status LEDs used to monitor traffic activity, alerts and provide status.
According to Dr. Mordechai Guri, head of research and development at the BGU CSRC, who led this study, "Sensitive data can be encoded and sent via the LED light pulses in various ways. An attacker with access to a remote or local camera, or with a light sensor hidden in the room, can record the LED's activity and decode the signals."
"Unlike network traffic that is heavily monitored and controlled by firewalls, this covert channel is currently not monitored. As a result, it enables attackers to leak data while evading firewalls, air-gaps (computers not hooked up to the internet) and other data-leakage prevention methods," Dr. Guri says.
The xLED malware can program the LEDs to flash at very fast speeds – more than 1,000 flickers per second for each LED. Since a typical router or network switch includes six or more status LEDs, the transmission rate can be multiplied significantly to as much as thousands of bits per second. As a result, a significant amount of highly sensitive information can be encoded and leaked over the fast LED signals, which can be received and recorded by a remote camera or light sensor.
The CSRC has a dedicated research program to uncover and demonstrate vulnerabilities of electronic devices. Over the past two years, they have successfully demonstrated how malware can siphon data from computer speakers, headphone jacks, hard drives, and computer fans, as well as 3D printers, smartphones, LED bulbs, and other IoT devices.
In addition to Dr. Guri, the other BGU researchers include Boris Zadov, who received his M.Sc. degree from the BGU Department of Electrical and Computer Engineering; Andrey Daidakulov, CSRC security researcher, and Prof. Yuval Elovici, director of the BGU Cyber Security Research Center. Prof. Elovici is also a member of BGU’s Department of Software and Information Systems Engineering and director of Deutsche Telekom Innovation Laboratories at BGU.