New InjectEave technique allows eavesdropping via electromagnetic signals

Researchers from The Hong Kong University of Science and Technology and The Hong Kong Polytechnic University have developed a new method called InjectEave that can eavesdrop on audio signals processed by analog components in various devices, including headphones and landline phones, by injecting electromagnetic signals. This technique overcomes the challenge of faint RF signals in devices, which previously made them difficult to exploit due to low signal-to-noise ratios. The InjectEave method actively manipulates signals rather than passively capturing them, potentially allowing attackers to modulate and capture audio signals that are otherwise hard to detect, according to a recent report by The Register.

InjectEave is an electromagnetic side-channel attack that targets non-linear analog components found in many electronic devices, such as amplifiers and converters. By transmitting a signal in the 0-9 MHz range, an attacker can modulate an otherwise undetectable audio signal, making it capturable by nearby equipment. The researchers demonstrated that this attack can recover headphone audio from up to 30 meters away, even through walls, and has been verified on multiple commercial devices from brands like Sony, HP, and Philips.

The attack is effective against analog paths and is immune to digital defenses like encryption. While hardware-aware mitigations such as shielding and filtering can reduce the risk, they do not guarantee complete immunity. The technique could be used for espionage or to infer activities in smart homes by monitoring signals from devices like smart fans and lamps.

Source: The Register