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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

#261
Turning off camera LEDs and recording video is an old hack and old news. This is for a specific firmware and computer model and attack surface via USB to update the webcam's firmware, so I am assuming that makes it news?

EDIT: I keep a piece of black electric tape over any of my notebook's webcams.

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

#262
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…

> and no firmware is involved in enforcing the LED stay on for 3 seconds after a single frame is captured.

I may be the oddball here, but that 3 second duration does not comfort me. The only time I would notice it is if I am sitting in front of the computer. While someone snapping a photo of me while working is disconcerting, it is not the end of the world. Someone snapping photos while I am away from the screen is more troublesome. (Or it would be if my computer was facing an open space, which it doesn't.)

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

#263
post #163

Earlier quoted context omitted.

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…

There seems to be widespread anxiety regarding cameras, but hardly anyone ever talks about microphones. Are conversations not much more privileged information than potentially seeing someone in their underwear?

"All Apple silicon-based Mac notebooks and Intel-based Mac notebooks with the Apple T2 Security Chip feature a hardware disconnect that disables the microphone whenever the lid is closed. On all 13-inch MacBook Pro and MacBook Air notebooks with the T2 chip, all MacBook notebooks with a T2 chip from 2019 or later, and Mac notebooks with Apple silicon, this disconnect is implemented in hardware alone." [1]

[1] https://support.apple.com/guide/security/hardware-microphone...

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

#264
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…

I assume you're not longer working on it, but why not just wire it so that:

- The LED is in parallel, but with the sensor voltage supply, not the chip

- Camera sensor idle voltage = low voltage for the LED (be it with stepping if needed)

- Camera sensor active voltage = high voltage for the LED (again, stepping if needed)

- little capacitor that holds enough charge to run the LED for ~3 seconds after camera goes back to idle voltage.

Good luck hacking that :)

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

#265

Earlier quoted context omitted.

An indicator light hardwired is nice but I apparently can't trust hardware manufacturers to design it properly. My work laptop (HP Dragonfly) has a physical blocker that closes over the camera when I haven't explicitly pressed the button that enables the camera. The blocker is black and white stripes so it's very obvious when it's covering the sensor. This should absolutely be the security standard we all strive for…

> The blocker is black and white stripes On my ThinkPad it’s instead painted with a red dot. Because, obviously, the conventional meaning of a red dot appearing on a camera is “not recording”.

Not just the weird meaning, but on my last Thinkpad the red dot and the slightly red glean of the camera lens look surprisingly like each other. Even worse I managed to get the cover in a position where it looked like it was closed, but the camera could still see.

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

#266

Earlier quoted context omitted.

I believe it is possible to turn a speaker into a microphone. Found a paper which claims to do just that[0]. So, there is no safety anywhere? SPEAKE(a)R: Turn Speakers to Microphones for Fun and Profit It is possible to manipulate the headphones (or earphones) connected to a computer, silently turning them into a pair of eavesdropping microphones - with software alone. The same is also true for some types of loudspea…

Despite this being a 2016 paper, it's worth noting that this is true in general and has been common(ish) knowledge among electrical engineers for decades. Highschoolers and undergrads in electrical engineering classes often discover this independently. What's notable about this paper is only that they demonstrate it as a practical attack, rather than just a neat fun fact of audio engineering. As a fun fact, an LED ca…

Yes! LEDs as photometers is something that you don't really see around much anymore, but it is really cool. Even an LED matrix can be used as a self-illuminating proximity sensor with the right setup.

https://www.youtube.com/watch?v=GaAtpAuNN_o

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

#267
this is so widespread and simple that i basically don't have any respect for laptop manufacturers who refuse to add a simple webcam shutter onto their laptop designs

what would be even better is PHYSICAL HARDWARE POWER SWITCHES for microphones, speakers, and webcam

this ought to be a manufacturer regulation, no more ridiculousness

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

#268
post #262
post #163

Earlier quoted context omitted.

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…

> and no firmware is involved in enforcing the LED stay on for 3 seconds after a single frame is captured. I may be the oddball here, but that 3 second duration does not comfort me. The only time I would notice it is if I am sitting in front of the computer. While someone snapping a photo of me while working is disconcerting, it is not the end of the world. Someone snapping photos while I am away from the screen is m…

OK, but then what? Leave the LED on for 24 hours after you've captured a single frame? At that point the LED isn't really indicating camera usage because you'll just get used to seeing it on all the time whether the camera is in use or not.

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

#269
post #261

Turning off camera LEDs and recording video is an old hack and old news. This is for a specific firmware and computer model and attack surface via USB to update the webcam's firmware, so I am assuming that makes it news? EDIT: I keep a piece of black electric tape over any of my notebook's webcams.

Many assume that led indicators are tied to hardware rather than firmware. And this just proves that it is still not always the case.

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

#270
post #262
post #163

Earlier quoted context omitted.

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…

> and no firmware is involved in enforcing the LED stay on for 3 seconds after a single frame is captured. I may be the oddball here, but that 3 second duration does not comfort me. The only time I would notice it is if I am sitting in front of the computer. While someone snapping a photo of me while working is disconcerting, it is not the end of the world. Someone snapping photos while I am away from the screen is m…

It's strange that none of these companies will include a closable cover for the camera. I got one aftermarket. It is very reassuring since no hacking or accidental misclicks on my part can move the cover.
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