Apple's T2 security chip disconnects a MacBook's microphone when users close the lid

Feature only available for MacBook Pro and MacBook Air models released in 2018.

Apple revealed today that all new notebooks that come with a built-in T2 security chip will now disconnect the built-in microphone at the hardware level when users close their devices' lids. This new security enhancement is meant to prevent malware from secretly recording users.

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This new security feature was announced today at an Apple event held in Brooklyn, New York, where Apple also revealed the MacBook Air 2018, Apple's latest update to the company's successful line of MacBook notebooks.

"All Mac portables with the Apple T2 Security Chip feature a hardware disconnect that ensures that the microphone is disabled whenever the lid is closed," said Apple in a white paper that detailed T2's security features.

"This disconnect is implemented in hardware alone, and therefore prevents any software, even with root or kernel privileges in macOS, and even the software on the T2 chip, from engaging the microphone when the lid is closed."

T2 is a secure co-processor that is embedded in modern Apple devices. They work separately from the main CPU, and they're used to handle encryption-related operations in a secure, hard-to-tamper chipset. On modern Macs, T2 chips are foundation for new features like the APFS encrypted storage system, a more robust secure boot process, and the TouchID authentication on Macs.

Apple started shipping products with its new T2 security chip earlier this year, in January. The iMac Pro and the MacBook Pro models from 2018 have already come with the new T2 chips.

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However, the new microphone hardware-level disconnect will only be available to "Apple portables," meaning MacBook devices --because you obviously don't have lids on iMacs.

The microphone hardware-level disconnect feature wasn't mentioned in a January edition of Apple's T2 chip white paper, or in later promotional materials released over the summer, meaning it's a new feature added for the MacBook Air 2018's release.

It's very likely that existing T2-capable MacBook Pro models will require some sort of software update before being able to take advantage of this feature. ZDNet will update the story once we find out more.

While Apple hasn't explicitly spelled it out in the October version of the T2 chip white paper, the new feature was likely added to prevent malware or intrusive apps from secretly recording users when they close their lids, and when users normally believe the device and OS are in a suspended state.

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Once the lid is open, the idea is that users will either rely on an antivirus capable of detecting running malware or apps like OverSight that alert the user when a Mac process --legitimate or not-- tries to access a device's microphone or camera.

Apple also said it didn't configure the T2 chip to disconnect the camera at the hardware level similar to the microphone because it was pointless as the camera's field of view is obstructed anyway when the user closes the lid.

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