Silently Hacking Alexa, Siri, and Google Now with Ultrasonic Sound

Introducing DolphinAttack: Hacking Digital Voice Assistants using High-Frequency Audio

Recently, researchers demonstrated how a hacker can command your voice assistant (Siri, Alexa, etc), using Ultrasonic sound — A.K.A sound that humans cannot hear.

DolphinAttack: Inaudible Voice Commands:

The researchers show how one can construct modulated audio snippets of which the voice assistant will respond to. These modulated audio snippets cannot be detected by human ears. These sounds are usually above 20,000Hz (10kHz).

In my opinion, this attack surface is about to lead to some interesting vectors if manufacturers cannot begin making consumer microphones that don’t listen above 20kHz.