Ultrasounds emitted by ads or JavaScript code hidden on a page accessed through the Tor Browser can deanonymize Tor users by making nearby phones or computers send identity beacons back to advertisers, data which contains sensitive information that state-sponsored actors can easily obtain via a subpoena.
This attack model was brought to light towards the end of 2016 by a team of six researchers, who presented their findings at the Black Hat Europe 2016 security conference in November and the 33rd Chaos Communication Congress held last week.
Their research focuses on the science of ultrasound cross-device tracking (uXDT), a new technology that started being deployed in modern-day advertising platforms around 2014.
uXDT relies on advertisers hiding ultrasounds in their ads. When the ad plays on a TV or radio, or some ad code runs on a mobile or computer, it emits ultrasounds that get picked up by the microphone of nearby laptops, desktops, tablets or smartphones.
These second-stage devices, who silently listen in the background, will interpret these ultrasounds, which contain hidden instructions, telling them to ping back to the advertiser's server with details about that device.
-- submitted from IRC
(Score: 2) by tangomargarine on Monday January 09 2017, @04:05PM
and when I unplug it, it can't be turned on remotely.
Cutting off its power source usually works pretty well. Unless of course it's physically built into the device and/or has a battery.
Wrapping stuff in tin foil is sounding less crazy every day. How much of a barrier do you have to put around a cell phone to block the signal anyway? Considering that basically going into a room in any random house without windows is often enough to do it :P
"Is that really true?" "I just spent the last hour telling you to think for yourself! Didn't you hear anything I said?"
(Score: 2) by tangomargarine on Monday January 09 2017, @04:13PM
anecdata of potato chip bag blocking [ubuntuforums.org]
"Is that really true?" "I just spent the last hour telling you to think for yourself! Didn't you hear anything I said?"
(Score: 2) by Arik on Monday January 09 2017, @04:43PM
If laughter is the best medicine, who are the best doctors?
(Score: 2) by Osamabobama on Tuesday January 10 2017, @12:43AM
If you're just trying to block the ultrasonic audio tags, the faraday bags aren't the best option. A pillow would be a good low-pass filter, but a shoebox might work just as well. Ultrasonic audio is easily attenuated.
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