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Yandex Apps Leak Pre-Trigger Audio Buffers, Payment Data, and Contacts via Reverse Engineering

Reverse engineering of Yandex Search and Yandex Browser APKs reveals extensive data collection practices on Android devices. The apps maintain a server-controlled pre-trigger audio buffer that captures up to three seconds or more of microphone input before the wake word Alice is detected. WiFi fingerprinting, full contact book synchronization via ContentObserver, and transmission of PAN and CVV details to mobpayment.yandex.net occur before tokenization. Additional findings include 94 JavaScript Bridge methods, logcat exfiltration with AES encryption, hardcoded Yandex DNS servers, and a native surveillance library named libquarkenstein_daemons.so. The analysis also covers passive geolocation, cell tower data collection, and inventory of installed applications including competitors such as Chrome, Firefox, WhatsApp, and Telegram. These mechanisms operate under remote configuration flags and bypass several Android privacy restrictions through manifest queries.