BadBIOS: A Feasibility Study of Ultrasonic Communication Between Air-Gapped Computers

Authors

  • Nika Hočevar Univerza v Ljubljani, Fakulteta za računalništvo in informatiko
  • Aleks Klopčavar Univerza v Ljubljani, Fakulteta za računalništvo in informatiko

DOI:

https://doi.org/10.31449/upinf.299

Keywords:

BadBIOS, Ultrasonic communication, Malware, air-gapped computers, covert communication channels, BFSK

Abstract

BadBIOS is a purported malware system that has been associated with claims of communication between physically isolated computers. The technical feasibility of such communication using ultrasonic data transmission without specialized equipment was investigated. A communication system based on Binary Frequency Shift Keying was implemented using frequencies of 18.5 kHz and 19.5 kHz. The system was tested on five computers running different operating systems, using integrated speakers and microphones. Under the tested conditions, data transmission was achieved at distances of up to 8 m, while reception performance varied between devices, primarily due to differences in audio hardware. The results confirm the technical feasibility of ultrasonic communication without specialized equipment, but do not confirm the existence of BadBIOS or any of its other alleged capabilities.

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Published

2026-10-27

Issue

Online-first

Section

Professional papers

License

Copyright (c) 1970 Applied Informatics

Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 International License.

How to Cite

[1]
2026. BadBIOS: A Feasibility Study of Ultrasonic Communication Between Air-Gapped Computers. Applied Informatics. (Oct. 2026). DOI:https://doi.org/10.31449/upinf.299.