Shazam for Mac keeps mic recording when 'off'

Reverse-engineering of Shazam's macOS app found it continues recording from the internal microphone even after the user toggles it 'OFF', though it doesn't appear to process or exfiltrate the audio.

A researcher reversed the Shazam macOS application after a user reported that OverSight (a tool that alerts on webcam/mic access) never showed a 'Mic Deactivation' event when Shazam was toggled off. Deep analysis of the Objective-C code and ShazamSDK.framework revealed that toggling the app to 'OFF' only stops the app from processing captured audio (via a 'generating' flag) rather than actually halting the low-level AudioOutputUnitStop() call that would stop the microphone stream. The 'taggingType' value is hard-coded such that the condition needed to trigger 'stopRecording' is never satisfied, meaning the mic remains active and recording continues in the background regardless of the UI toggle state.

The researcher found no evidence that this recorded audio is saved, processed, or exfiltrated when the app is in the 'OFF' state — the flaw appears to be an oversight rather than intentional spying. However, the behavior is concerning from a privacy standpoint, as it means malware or a compromised process could potentially piggyback on this always-on recording state without triggering typical mic-activation alerts. The researcher contacted Shazam prior to publication; the vendor confirmed the technical findings and indicated a fix would be addressed in a future update.

This is a privacy/behavioral disclosure rather than an active exploit or malware campaign — no IOCs, threat actors, or active exploitation are involved. It serves as a case study in how legitimate apps can inadvertently retain sensitive hardware access beyond user-intended controls, and highlights the value of tools like OverSight for auditing mic/camera usage on macOS.

Source reporting: https://objective-see.org/blog/blog_0x13.html