Demo: Emissions Turn Speakers Into Remote Listening Device

Our devices have their own electromagnetic emissions. This can lead to unexpected effects.

These emissions give off a unique signature. So unique in fact each device can be fingerprinted by it, and identified by its model.

Another concern is what is referred to as Van Eck Phreaking (based on Van Eck) or “tempest.” Your LCD carries unique emissions dependent on what is being viewed on your screen. This can lead to remote viewing of the picture on your monitor [Van Eck Phreaking].

Speakers/headphones make up a similar design to microphones. Using SDR the other day I discovered a few frequencies the other day where with careful filtering I was able to “tap in” to my laptop’s sound. By tuning/filtering properly I was able to make out the sounds not only coming from my speakers, but also speaking in the room, turning my speakers into a remote listening device.

I made a video on the topic with a demonstration. I used Parrot to both make the video in KDENLIVE and towards the end, I show how to clean up the audio in Audacity. The video also features Pine64’s Pinetab (I was lucky enough to get one from them (big thank you to them) before they paused selling them - shortages in hardware are hitting everyone hard).

The audio was remotely recorded using dipole antenna roughly 15 feet away (have not checked further as signal was still rather weak, but words were understandable).

The entire start to finish process can be performed on Parrot using SDR software
(apt search sdr).

I thought the finding was interesting and wanted to share it with the Parrot Community.

See the video demo here:

I may try to compile TempestSDR to experiment with remote LCD viewing.

Anyone ever worked with Tempest software?

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Great video, that’s really cool! I was aware of these kinds of attacks but had no idea they are so easy to deploy. Unfortunately I don’t have an SDR but at some point I’m definitely going to do some experiments like this for myself.

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Thank you for the feedback. :slight_smile:

RTL-SDR Blog v3 is nice if you want something affordable to start with, and has more capability than some of the generic (if you want to listen to Ham bands). Although I did use a generic in this case as it came with my device and worked for this purpose just as well.