AliExpress Uses WebAudio API and Zero-Gain Audio Graphs for Silent Device Fingerprinting
Brief
AliExpress’s homepage quietly builds hidden WebAudio processing graphs in the browser, a technique that appears to power an aggressive device-fingerprinting system while producing an unexpected real-world side effect: interfering with Bluetooth multipoint audio switching on connected headphones.
Security researcher Laserphile, using multipoint Bluetooth headphones that stay simultaneously paired to a PC and a phone, noticed that opening the AliExpress homepage in Firefox or Chrome would abruptly cut off audio playing from their phone.
AliExpress Uses WebAudio API for Device Fingerprinting
Muting the browser tab, the entire browser, or even Windows system audio did nothing to restore playback. Only closing the AliExpress tab fixed the issue immediately, despite no visible video, audio player, or media content anywhere on the page.
Standard troubleshooting turned up nothing.