Serious Hacks Possible Through Inaudible Ultrasound (newscientist.com)

An anonymous reader writes: "High-frequency audio 'beacons' are embedded into TV commercials or browser ads," reports New Scientist. "These sounds, which are inaudible to the human ear, can be picked up by any nearby device that has a microphone and can then activate certain functions on that device...Some shopping reward apps, such as Shopkick, already use it to let retailers push department or aisle-specific ads and promotions to customers' phones as they shop."

But now Fortune reports that some apps "often actively listen for ultrasound signals, even when the app itself is closed, creating a new and relatively poorly-understood pathway for hacking." In addition, security researchers "have already found ways to mine cloaked IP addresses. Speaking to New Scientist, team member Vasilios Mavroudis suggests that an app's always-on microphone access could be leveraged to monitor conversations (and, if you're not paranoid already, to decipher what you're typing). The 'beacons' that transmit ultrasound data can also be spoofed to manipulate apps' user data."

Comments

Re:What?

[AK Marc]

What happens when these "ultrasound" sounds try to pass through high end speakers with bandfilters? My ribbon tweeters can destroy themselves with ultrasound, so they have low-pass bandfilters (and high-pass bandfilters, where the mids take over). So what speaker is passing these sounds, and why are they getting past my bandfilters? How about the crappy sound system in my car? The speakers are rated to 15 kHz, so how are they passing 20+ kHz sounds?

The reason this sounds absurd is because it is.