TrojPix Turns Screens Into Covert Transmitters for Air-Gapped PCs
Researchers from Shandong University demonstrated TrojPix, a covert-channel that leaks data from air-gapped PCs by modulating on-screen pixels to emit a signal over video cables. In tests it achieved up to 8.1 Mbps throughput and up to 208 meters range (measured separately). It requires malware on the target but no admin rights or hardware changes, and uses two methods to hide the traffic: spoofing a dark display or embedding signals in visible content. It works across multiple monitor brands and cables, but real-world range will be affected by walls and shielding. Mitigations include using fiber-optic video, shielding, TEMPEST practices, and keeping malware off the machine. The work is currently lab-based and adds to a family of screen-based leakage techniques.
