Voice assistant devices can be secretly controlled by hackers using ultrasonic waves.

By sending ultrasonic waves through solid materials, researchers have found a new way to attack voice-controlled devices. This allows them to communicate with the devices and compromise them using inaudible voice commands without the victims’ knowledge.A unique feature of acoustic transmission in solid surfaces, like tables, is exploited by the “SurfingAttack” attack to “allow repeated rounds of interactions between the voice-controlled device and the attacker over a longer distance and without the requirement to be in line-of-sight.”The researchers described in the study that by doing this, an attacker may covertly take control of the victim device by exploiting the voice assistants, intercepting SMS two-factor authentication codes, and even making phony calls.