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Comment by notable_user | Hacker News Reader

This only protects when the lid is closed, but many people leave the lid open on their desk.

I would love to see a light come on if the camera or microphone is receiving power, and then only turn on power to these devices when a program requests it.

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The camera already functions this way. The light is connected to the actual power of the camera and cannot be disabled unless the camera is also disabled. The microphone, to my knowledge, doesn't function like this but I don't think it makes sense for it to function like this as the microphone doesn't really need power outside of what's provided to the amps and DACs inside the machine. It would be too easy to work around. Any membrane capable of vibration would be able to be used as a microphone, including the laptop's speakers, so it'd be more work for little gain.

> The light is connected to the actual power of the camera and cannot be disabled unless the camera is also disabled.

This was proven false when malware was discovered that accessed the camera on Mac laptops without activating the LED light. It's mentioned in the article.

The reasearch to prove that vulnerability was done on Macs made up until 2008 if I’m not mistaken. It’s not clear if that attack is still possible.

Which Macs still have a light?

I believe they all do, but I haven’t been able to find a document to confirm that.

Am I the only one who has tape over my laptop camera? (Specifically a peppa pig sticker)

I bought these for all the laptops being used by my family. Especially useful when you are in a group video conference and you need a quick and foolproof way to blank the video.

https://www.aliexpress.com/item/2018-WebCam-Cover-Laptop-Cam...

I have an EFF sticker specifically for this.

The article TechCrunch links to, about Patrick Wardle’s research on the FruitFly malware, actually never mentions defeating the webcam LED: https://www.zdnet.com/article/new-analysis-fruitfly-mac-malw...

It’s possible that Wardle’s Black Hat paper does, but the link doesn’t back up the assertion in the TechCrunch piece.

This was not proven false. The malware that was discovered only affected iMacs and MacBooks from 2008 and prior when the light was not directly connected to the camera's power. That didn't happen until early 2009.

> I would love to see a light come on if the camera or microphone is receiving power, and then only turn on power to these devices when a program requests it.

Isn't the microphone a simple passive device no different than a voice coil in a magnetic field? I don't think it's that simple, since it won't be powered.

My understanding is that there's often a reconfigurable circuit in the sound chip which determines where the lines in and out are routed. So even if you've physically disconnected the microphone, but left internal speakers connected, it's possible to turn the speakers into a microphone via software alone.

There's at least a pre amp and a d/a converter that the mic needs to have powered up and running before any of it's signal can be used by the rest of the computer.

Which will all be inside an IC, away from the microphone.

So what, does the light turn on whenever the entire IC sees power? Because if it relies on a signal from within the software-controlled IC, that's not exactly trivial to audit.

The trivial solution would be a LED + resistor just wired across the mic's power rails.

When the microphone is a passive connected to a multifunction IC there's no such power rail.

Most laptop mics are condenser electret mics which usually use a small dc current, although not always.

Not the last time I went down this road hardening a Thinkpad, see Step 6 at [1] (not my site). I haven't bothered with any smartphones yet, so I can't speak to what they tend to use for a mic. But if I carried one I'd definitely rip out all the voice coils and rely on a pair of headphones w/integrated mic for voice comms to mitigate potential for eavesdropping.

[1] https://blog.patternsinthevoid.net/replacing-a-thinkpad-x60-...

When replacing the lightning assembly on my iPhone 6, I noticed that the microphone looks passive. Here’s a photo[0]; It’s the little bronze(?) square next to the headphone jack.

[0]: https://www.ifixit.com/Store/iPhone/iPhone-6-Lightning-Conne...

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