Recent research shows that ordinary earbuds and headphones can be repurposed into spying microphones thanks to experimental malware dubbed “Speake(a)r”.
The proof-of-concept malware, developed by researchers from Israel’s Ben Gurion University, works by altering RealTek’s audio codec chips to transform the output channel into an input channel. In turn, any connected headphones can be turned into a microphone by using their membrane to pick up sound vibrations and converting them into electromagnetic signals.
“People don’t think about this privacy vulnerability,” says Mordechai Guri, the research lead of Ben Gurion’s Cyber Security Research Labs. “Even if you remove your computer’s microphone, if you use headphones you can be recorded.”
Because RealTeck chips are extremely common on computers running either Windows or MacOS, researchers believe the proof-of-concept could be used at a large scale. With the ability to record from as far as 20 feet away, the malware can even be instructed to compress the audio without losing quality.
While no patch is currently available to fix the vulnerability, researchers believe there’s little affected users can do apart from disabling all audio input and output from the computer. The research also proposes a series of hardware and software countermeasures that defeat the malware, each with its advantages and drawbacks.
“Software countermeasures may include disabling the audio hardware in the UEFI/BIOS settings. This can prevent a malware from accessing the audio codec from the operating system. However, such a configuration eliminates the use of the audio hardware (e.g., for music playing, Skype chats, etc.), and hence may not be feasible in all scenarios,” reads the paper. “Other hardware countermeasures include white noise emitters and audio jammers which offer another type of solution aimed at ruining audio recordings by transmitting ambient sounds that interfere with eavesdroppers and don’t allow them to accurately capture what is being said.”
While other measures have been proposed for mitigating this attack, researchers concluded that even PCs without built-in microphones can be turned into eavesdropping devices, with the right malware.