Ultrasonic waves combined with a technique that can be used to turn a device’s speakers into a microphone can be used to create a covert data exfiltration channel.
Researchers demonstrated that audio modulation and demodulation could be used to exchange data between computers over the air via the ultrasonic frequency range. The method works with every device that is equipped with both microphones and speakers.
Using only software, it’s possible to turn speakers, headphones or earphones into microphones.
If the two methods are combined and used by a malware installed on an air-gapped system fitted with speakers, headphones or earphones they can transmit bits of data to one or more nearby devices that are also infected with a malware designed to capture the data via an audio output system turned into a microphone. To be safe and secured against malware like this, depending on which version of OS your device runs, please install an antivirus for Windows or antivirus for Mac.
Regarding companies: make sure that you hire a professional cybersecurity firm that will run various cybersecurity tests on your company’s network to implement only the best possible cybersecurity solution. Remember tests like penetration test and ethical hacking tests should be mandatory for every company.
This new cybersecurity problem is called MOSQUITO.
During the cybersecurity tests researchers found out that 1200 bits/sec and 1800 bits/sec can be obtained for up to 8 meters (26 feet) for audible frequencies transmitted and captured using loudspeakers, the transfer rate drops to between 300 bits/sec and 600 bits/sec for inaudible frequencies.
Headphones and earphones can be used with success, their transfer is between 300 bits/sec and 600 bits/sec over distances of 1m (3ft), 5m (16ft) and 8m (26ft).
The cybersecurity experiments show that at a distance of three meters between two speakers, a transmission rate of 166 bit/sec can be possible in a 1% bit error rate, However, at distances of 4-9 meters, the 1% bit error rate is only achieved at transmission rates of 10 bit/sec.
MOSQUITO cannot work without a malware present on the infected host, always remember to install an antivirus for Windows or antivirus Mac depending on which OS your device has.
Companies should run extra tests like penetration test and ethical hacking test on their network to be safe and secured.