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+--- Thread: Demo: Speakers Become Unintentional Remote Listening Devices (Using Pinetab/GQRX) (/showthread.php?tid=13475)
Demo: Speakers Become Unintentional Remote Listening Devices (Using Pinetab/GQRX) - RTP - 03-23-2021
Made a video demonstrating something I discovered while using Pinetab's internal RTL-SDR (using GQRX).
I found my Lenovo laptop's speakers (whenever playing any form of sound/video) turn into a virtual microphone, remotely transmitting all audio in the room to multiple frequencies.
When in use, my (Lenovo) laptop speakers turn themselves (speakers on Lenovo laptop) into an unintentional remote listening device. Anytime sound is played from those Laptop speakers (Lenovo example), the speakers turn into a microphone, and combined remote transmitter (speakers are very similar to microphones).
I was able to tune into these frequencies using the Pinetab w/built in rtl-sdr, and found the frequencies to be static, reliable locations to listen in (bookmarked and repeated many times).
Unique electromagnetic emissions are given off by our devices (while in use). In some cases speaker wires themselves (not normally shielded well), can turn into a virtual transmitting antennas.
in this case the remote transmitting only occurs when speaking is playing audio. In other cases high powered electromagnetic energy can remotely turn devices into listening devices. This is known as RF retro reflecting.
After talking about these things (in the below video), I show GQRX on the Pinetab tuning into a couple of these frequencies.
I record the speaker's signals and replay the raw audio captured from GQRX.
Then I demo how to clean up these audio signals and replay the audio (making for a much cleaner sounding recording with understandable words).
Check out the video here: https://youtu.be/bK-CcnfP_ws