We all know how smart speakers work: you give them an order with your voice and almost immediately they execute it. The sound waves propagate and are received by your assistant's microphone diaphragm, which translate into electrical signals that Alexa or Siri can understand. In theory it takes the voice to make them work, but this group of researchers found that they can be hacked using only one laser beam.
We also recommend: If you do not update WhatsApp this security flaw may affect you
A group of researchers from the University of Michigan, United States, managed to hack a smart speaker using only a laser beam. They discovered that the necessary command to access the device could be encoded in the light beam of a laser. That way the light signal causes the speaker diaphragm to receive the electrical signals as if it were receiving a voice command.
Investigators they managed to hack Siri, Alexa and other virtual assistants up to 110 meters away from the device using a laser beam. They also managed to access an intelligent speaker located in a building from a bell tower located 70 meters from the building, pointing the beam through a window.
The equipment needed to hack a smart speaker at an average distance costs about $ 400, the researchers said. But if what is needed is a long-distance attack the price can increase to 600 dollars.