Researchers prove any headphone could be used for eavesdropping
The malware can now hijack a user’s headphones and turn them into an audio recording device.
Headphones and earphones are generally used to soak in your favourite tunes, but did you know that can also be used to covertly listen in to conversations and record audio? Cybersecurity researchers at Israel’s Ben Gurion University recently demonstrated that it is possible to convert a headphone--which is conventionally an audio playback device--into an audio recording device, much like a microphone.
The physical construction of a microphone and a pair of headphones is actually identical. They both comprise a mechanism that causes sound vibrates (in the case of headphones) or themselves vibrate due to external sound (in microphones.) So in principle, it is actually possible to have one to do the job of the other, simply by reversing its operation. While this has in fact been done my numerous tinkerers, as the multitude of videos on YouTube indicate, the method demonstrated by the Israeli researchers is actually more subversive--they wrote a code that uses the audio chip in a laptop or a smartphone to switch the functionality of a headphone jack (which is an output jack) into that of a microphone jack (and input jack.)
Most audio chipsets in computers and smartphone do in fact have this functionality built right in--using the device’s application software, a headphone socket can be toggled to act as a microphone port. However, a hacker being able to switch this functionality without the user’s knowledge could effectively lead to eavesdropping when a pair of earphones are connected.
The researchers demonstrated this vulnerability with the RealTek audio codec chip--a popular piece of hardware used in numerous devices. The malware, known as ‘Speake(a)r,’ was shown to function on both Windows and MacOS, so it could typically be used to compromise millions of desktops and laptops based on this audio chipset.
For the security-obsessed, apart from taping up your webcam to prevent a hacker from peeking into your life, it appears you’ll now also need to conscientiously unplug your headphones when you’re not using them.