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Malware can turn off webcam LED and record video, demonstrated on ThinkPad X230

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Re: Malware can turn off webcam LED and record video, demonstrated on ThinkPad X230

#181

Earlier quoted context omitted.

There's lots of people who aren't "serious about video meetings" but still want to be able to do a face-to-face chat with family or whatnot.

So get a $15 USB webcam.

That would be yet another gadget (with yet another tangly wire) to add to your bag. One of the best things (and one of the worst things, if you're interested in repairability and upgradability) of a laptop is that everything (other than the external power adapter) is built-in.

Re: Malware can turn off webcam LED and record video, demonstrated on ThinkPad X230

#182
post #163
post #81

Earlier quoted context omitted.

I believe that it’s not literally hardwired in the sense that powering up the camera also powers up the camera LED, and instead this relies on logic in the hopefully un-flashable camera+LED firmware. Someone correct me if I’m wrong. You need some logic to enforce things like a minimum LED duration that keeps the LED on for a couple seconds even if the camera is only used to capture one brief frame. I have a script th…

I happen to have some first-hand knowledge around the subject! In 2014 someone did a talk[0] on disabling the camera on some older Macbooks. It was fairly trivial, basically just reflashing the firmware that controlled the LED. I worked on the security team at Apple at the time and in response to this I attempted to do the same for more modern Macbooks. I won't go into the results but the decision was made to re-arch…

Thank you for doing this.

Re: Malware can turn off webcam LED and record video, demonstrated on ThinkPad X230

#185
post #4

I assumed that most if not all of these webcam LEDs are wired in series with the power to the camera itself. Which then makes it impossible to disable them. Who designs this LED to be software addressable?

I'm not an EE by trade, but I personally wouldn't want to put a CCD in series with an LED with god-knows-what Vf tolerances. Then again, I'd bet that nearly all laptop webcams come as off-the-shelf modules with their own internal regulators for the CCD anyway. So maybe it wouldn't matter. I'll bet it went something like this: As originally specified, the user need was "LED privacy indicator for the webcam." Product m…

Could you wire it with a relay/transistor?

Re: Malware can turn off webcam LED and record video, demonstrated on ThinkPad X230

#186
post #118

Earlier quoted context omitted.

Interesting, my work HP Probook does not have that functionality. I wonder why HP chooses to do this only for some laptop lines.

I suspect most people don't want it. I can imagine lots of people calling customer service "Q: why doesn't my camera work?", "A: Did you open the cover?" There's just a valid an argument to do the same for phones. How many phones ship with camera covers and how many users want them? You can get a stick on camera cover for $5 or less if you want one. I have them on my laptops but not on my phone. They came in packs of…

It's also a moving part. Worse, a part the customer moves. Which means more opportunity for crap getting crammed in or breaking.

Re: Malware can turn off webcam LED and record video, demonstrated on ThinkPad X230

#187
post #163
post #81

Earlier quoted context omitted.

I believe that it’s not literally hardwired in the sense that powering up the camera also powers up the camera LED, and instead this relies on logic in the hopefully un-flashable camera+LED firmware. Someone correct me if I’m wrong. You need some logic to enforce things like a minimum LED duration that keeps the LED on for a couple seconds even if the camera is only used to capture one brief frame. I have a script th…

I happen to have some first-hand knowledge around the subject! In 2014 someone did a talk[0] on disabling the camera on some older Macbooks. It was fairly trivial, basically just reflashing the firmware that controlled the LED. I worked on the security team at Apple at the time and in response to this I attempted to do the same for more modern Macbooks. I won't go into the results but the decision was made to re-arch…

Thanks, this is the reason I browse Hacker News

Re: Malware can turn off webcam LED and record video, demonstrated on ThinkPad X230

#189

Earlier quoted context omitted.

This only works on audio chipsets that allow pin retasking. Which is, coincidentally, all Realtek chipsets that are present in every PC... (you also need to plug the speaker directly, mostly limiting it to headphones and laptop speakers)

Even where it works, speakers are much worse microphones that dedicated microphones, and so the amount of data that can be gathered is low. Why bother when you probably have a microphone on the same PC that can capture far more sound?

I think there was a long period where a proper PC would frequently have only the cheap stereo speakers which are small enough to far outperform raw microphone leads. But I'm not sure this works that well in >=HDMI even if some monitor speakers might otherwise be ideal.
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