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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

#41

Post by perching_aix »

sbarre wrote: post #3

I thought the whole point of these camera LEDs was to have them wired to/through the power to the camera, so they are always on when the camera is getting power, no matter what. Having the LED control exposed through the firmware completely defeats this.

For what it's worth, you could just power on the camera, take a pic, then turn it back off instead. Provided you can do this fast enough, an indicator LED is rendered worthless. So you'd need to make the indicator LED staggered, to stay lit for a minimum amount of time.

There's also the scenario where the LED or the connections to it simply fail. If the circuit doesn't account for that, then boom, now your camera can function without the light being on.

Can't think of any other pitfalls, but I'm sure they exist. Personally, I'll just continue using the privacy shutter, as annoying as that is. Too bad it doesn't do anything about the mic input.

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

#42

Post by TZubiri »

sbarre wrote: post #3

I thought the whole point of these camera LEDs was to have them wired to/through the power to the camera, so they are always on when the camera is getting power, no matter what. Having the LED control exposed through the firmware completely defeats this.

The idea has been around for quite some time. But it is always dropped.

My guess is that, assuming the most basic and absolute physicial design, the light would flash for silly things like booting, upgrading firmware, checking health or stuff like that.

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

#43

Post by salutis »

epistasis wrote: post #17

I can see why some people might be concerned about the camera, but I'm far more concerned by the microphone. There's far more sensitive and actionable information that can be gathered from me that way! I'm glad that macOS started putting a light in the menubar when the microphone is in use, but I'd prefer to have unhackable hardware for that instead.

macOS is a proprietary binary blob, remotely controlled by Apple. So, the light in the menu bar is not a reliable indicator of anything. There is no privacy on macOS, nor any other proprietary system. You can never be 100% sure what the system is doing right now, as can be anything it is capable of. Apple is putting a lot of money to "teach people" otherwise, but that is marketing, not truth.

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

#44

Post by TZubiri »

perching_aix wrote: post #41
sbarre wrote: post #3

I thought the whole point of these camera LEDs was to have them wired to/through the power to the camera, so they are always on when the camera is getting power, no matter what. Having the LED control exposed through the firmware completely defeats this.

For what it's worth, you could just power on the camera, take a pic, then turn it back off instead. Provided you can do this fast enough, an indicator LED is rendered worthless. So you'd need to make the indicator LED staggered, to stay lit for a minimum amount of time. There's also the scenario where the LED or the connections to it simply fail. If the circuit doesn't account for that, then boom, now your camera can…

A minimum light duration seems pretty trivial to physically engineer.

For one the energy to take a picture is probably enough to power a light for a noticeable amount of time.

And if it isn't, a capacitor that absorbs energy and only allows energy through once it's full would allow the light to remain on for a couple of seconds after power subsides.

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

#45

Post by criddell »

sbarre wrote: post #3

I thought the whole point of these camera LEDs was to have them wired to/through the power to the camera, so they are always on when the camera is getting power, no matter what. Having the LED control exposed through the firmware completely defeats this.

I can't find it now, but recently I read how one company's design team added this feature to their laptops. A subsequent review by the team responsible for manufacturing found that they could change the circuit to cut down on the part count to save money. The light was still there, but it was no longer hardwired. The company continued to advertise the camera light as being hardwired even though it wasn't.

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

#46

Post by adolph »

sbarre wrote: post #3

I thought the whole point of these camera LEDs was to have them wired to/through the power to the camera, so they are always on when the camera is getting power, no matter what. Having the LED control exposed through the firmware completely defeats this.

It isn't clear to me that webcam firmware ever powers down a typical camera module. See below for data about how the Sony IMX708 sensor is an I2C device with start and stop streaming commands.

https://github.com/Hermann-SW/imx708_regs_annotated?tab=read...

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

#47

Post by greenthrow »

TZubiri wrote: post #42
sbarre wrote: post #3

I thought the whole point of these camera LEDs was to have them wired to/through the power to the camera, so they are always on when the camera is getting power, no matter what. Having the LED control exposed through the firmware completely defeats this.

The idea has been around for quite some time. But it is always dropped. My guess is that, assuming the most basic and absolute physicial design, the light would flash for silly things like booting, upgrading firmware, checking health or stuff like that.

Flashing is easily fixed with a capacitor and also not a bad thing if it turns off when it loses power immediately. The only explanation that makes sense to me is it being separately controlled is a feature not a bug.

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

#48

Post by lxgr »

ragnese wrote: post #16
permo-w wrote: post #5

my ideapad has a native physical webcam cover. no idea why this isn't universal standard

Eh. If it's not a physical power-disconnect switch, one could imagine it still being able to record audio, which still sucks.

The microphone is usually not part of the camera assembly in modern laptops.

And there is usually more than one. For example, recent Macbooks have three, as far as I know.

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

#49

Post by MattGaiser »

paxys wrote: post #15
lxgr wrote: post #10

Arguably a much, much bigger problem are the (many) microphones of modern devices. These usually get neither an LED nor a switch, and unlike cameras can't easily be covered, nor pointed away from potentially sensitive topics/subjects.

No amount of microphones will ever be a bigger problem than a single compromising photo or video.

A photo may be merely embarrassing. You could get a lot of immediately useful information hearing my phone calls though.

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

#50

Post by TZubiri »

salutis wrote: post #43
epistasis wrote: post #17

I can see why some people might be concerned about the camera, but I'm far more concerned by the microphone. There's far more sensitive and actionable information that can be gathered from me that way! I'm glad that macOS started putting a light in the menubar when the microphone is in use, but I'd prefer to have unhackable hardware for that instead.

macOS is a proprietary binary blob, remotely controlled by Apple. So, the light in the menu bar is not a reliable indicator of anything. There is no privacy on macOS, nor any other proprietary system. You can never be 100% sure what the system is doing right now, as can be anything it is capable of. Apple is putting a lot of money to "teach people" otherwise, but that is marketing, not truth.

I get it, free software take, nothing new.

But this is a pretty extremist take. Just because a company doesn't push source code and you can't deterministically have 100% certainty, doesn't mean you can't make any assertions about the software.

To refuse to make any claims about software without source is as principled as it is lazy.

Imagine an engineer brought to a worksite, and they don't have blueprints, can he do no work at all? Ok, good for you, but there's engineers that can.

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