Researchers discovered a new attack method dubbed SurfingAttack that enables the attacker to control the voice-controlled device from over a longer distance.

With this attack method attackers can hijack a mobile Short Message Service (SMS) passcode, making ghost fraud calls without owners’ knowledge, etc.


To launch a SurfingAttack the attackers not required to stay in line-of-sight, it can be launched secretly without alerting users in physical proximity.

By injecting voice commands attackers can stealthily instruct the voice assistants to leak various secrets, such as an authentication code for money transfer sent via an SMS message.

Once the sensitive information leaked, some hidden devices may pickup the secret information and relayed back to the attacker.

Researchers said that the attack is Omni-directional, which works regardless of the target’s orientation or physical environment where the target resides. Second, the success of the attack is not impacted by objects on a busy tabletop.

The surfing attack was tested against 17 popular smartphones and 4 representative types of table, out of them it is successful with n 15 smartphones and 3 types of tables.

The main goal of the attacker is to remotely converse with the victim’s voice controllable device to inject unauthorized voice commands or to access sensitive information without the victim’s knowledge.

How does Attack Works?

The Audio capturing hardware in the voice-controllable systems generally includes a micro-electromechanical system (MEMS) which converts a mechanical vibration to a digital signal.

The attack leverages the non-linearity of the microphone circuits to inject inaudible commands to these systems.

Researchers tried the attack on different phones, here are the devices tested.

Also, the attack can be launched from a 30ft long distance.

Researchers published a paper titled “SurfingAttack: Interactive Hidden Attack on Voice Assistants Using Ultrasonic Guided Waves” detailing the attack.

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