Researchers from University of Washington designed a tool that can track body position and movements of the user, as well as other people in the device’s immediate locality. Researchers have involved remotely hijacking smart devices to play music embedded with repeating pulses that track a person’s position, body movements, and activities both near the device as well as through walls.
Using Covert Band, a software code researchers created to turn smart devices into active sonar systems to collect data on personal activity. Covert Band can use built-in microphones and speakers in a smart device, and controlled by remote.
With smartphone speaker, Covert Band sends out sound waves in the 18 to 20 kHz range. The sound waves reflected when they face objects in their path. Covert Band uses the device’s built-in microphones as a receiver to pick up these reflected sound waves. The smart device transmits this information to the attacker, who could be a few feet away or halfway across the globe.
Covert Band shows for the first time that through-barrier surveillance is possible using no hardware beyond what smart devices already have.
The research team tested Covert Band’s success using a smart devices. In both cases, Covert Band’s data used to decrypt repetitive movements to a range of up to 6 meters from the smartphone. Currently, Covert Band identifies and infer repetitive motions. More detailed inferences require manual analyses of data or additional tools.
The 18 to 20 kHz repeating pulses can hear accurately, and even pets might be able to hear it well. But in close observation, the researchers increased the volume of these repeating pulses, which made them audible.
To mask the sound, researchers covered Covert band’s pulses by playing songs or other audio clips over them. They identify the hacked version of the song 58 percent of the time, just slightly above the 50 percent accuracy.
According to researchers, soundproofing room can prevent attack through walls. Emitting a jamming signal at the same 18 to 20 kHz frequency range would also prevent hacked devices or attackers for gathering information.
Soundproofed rooms have no windows, and jamming signals would have to be sent the moment an attack is detected. Also, it could allow users to deactivate the speakers or microphones on their smart devices. In many cases, when the device is on, then its speakers and microphones are also on.