| Title | Brightness: Leaking Sensitive Data from Air-Gapped Workstations via Screen Brightness |
| Publication Type | Conference Paper |
| Year of Publication | 2019 |
| Authors | Guri, Mordechai, Bykhovsky, Dima, Elovici, Yuval |
| Conference Name | 2019 12th CMI Conference on Cybersecurity and Privacy (CMI) |
| Date Published | Nov. 2019 |
| Publisher | IEEE |
| ISBN Number | 978-1-7281-2856-6 |
| Keywords | Air gaps, air-gapped computers, air-gapped workstations, Brightness, camera receivers, composability, computer network security, Human Behavior, human factors, Metrics, optical covert channel, pubcrawl, resilience, Resiliency, screen brightness, screens (display), sensitive data, video streams |
| Abstract | Air-gapped computers are systems that are kept isolated from the Internet since they store or process sensitive information. In this paper, we introduce an optical covert channel in which an attacker can leak (or, exfiltlrate) sensitive information from air-gapped computers through manipulations on the screen brightness. This covert channel is invisible and it works even while the user is working on the computer. Malware on a compromised computer can obtain sensitive data (e.g., files, images, encryption keys and passwords), and modulate it within the screen brightness, invisible to users. The small changes in the brightness are invisible to humans but can be recovered from video streams taken by cameras such as a local security camera, smartphone camera or a webcam. We present related work and discuss the technical and scientific background of this covert channel. We examined the channel's boundaries under various parameters, with different types of computer and TV screens, and at several distances. We also tested different types of camera receivers to demonstrate the covert channel. Lastly, we present relevant countermeasures to this type of attack. |
| URL | https://ieeexplore.ieee.org/document/8962137 |
| DOI | 10.1109/CMI48017.2019.8962137 |
| Citation Key | guri_brightness_2019 |
Brightness: Leaking Sensitive Data from Air-Gapped Workstations via Screen Brightness