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.”

Read more of this story at Slashdot.

Source: Slashdot – Serious Hacks Possible Through Inaudible Ultrasound