tech
Inaudible sounds used to fingerprint browsers catch AliExpress red-handed
Is the technique outdated? Yes. Is it still creepy? Also yes.
TL;DR
- Researcher Matthew Callaghan found AliExpress using an inaudible audio fingerprinting technique.
- The technique uses obfuscated scripts to analyze WebAudio readings, creating a browser signature.
- Scripts set audio gain to zero to prevent user detection.
- Firefox version 118 (2023) implemented a fix by using its own math libraries, disabling the technique.
- Chrome and likely Safari are also immune due to using their own libraries.
- AliExpress employs numerous other fingerprinting methods.
- The web audio trick is likely an obsolete method left from previous tracking efforts.
- Browser developers are in a continuous race against new tracking methods used by websites.