SmartAttack: Smartwatches Used to Steal Data from Air-Gapped Systems

Researchers have unveiled a novel cyberattack technique, dubbed SmartAttack. This technique uses smartwatches as covert receivers for ultrasonic signals to exfiltrate data from air-gapped systems, computers physically isolated from any network to prevent unauthorized access.

Air-gapped systems are commonly used in highly sensitive environments such as government facilities, defense systems, and nuclear power plants. Although isolated, these systems can still be compromised through insider threats, such as rogue employees or state-sponsored supply chain attacks.

Once malware infiltrates such a system, it can operate silently in the background, leveraging hardware components to transmit data covertly. In SmartAttack, the malware uses the computer’s built-in speaker to emit ultrasonic frequencies, undetectable by human ears but detectable by the microphone in a nearby smartwatch.

Using a technique called Binary Frequency Shift Keying (B-FSK), the malware encodes data into sound frequencies—18.5 kHz for binary “0” and 19.5 kHz for binary “1.” The smartwatch then captures and decodes these signals using signal processing algorithms. The collected data, such as keystrokes, credentials, or encryption keys, can later be transmitted via Wi-Fi, Bluetooth, or cellular networks.

SmartAttack was developed by a team of Israeli researchers led by Mordechai Guri. Guri is known for his work on covert data leakage methods using hardware-side channels, such as LCD noise, USB emissions, and power fluctuations.

While such attacks are complex and largely theoretical, they underscore the growing sophistication of cyber-espionage techniques and the ongoing vulnerability of even the most secure systems.