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Don't close your MacBook with a cover over the camera

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Re: Don't close your MacBook with a cover over the camera

#251

Post by Traster »

etaioinshrdlu wrote: post #15

> The camera is engineered so that it can’t activate without the camera indicator light also turning on. Has anyone torn down the hardware and verified this lately? It should not be a complicated feature at all. Just ensure you have the same voltage applied to your LED circuit as your camera circuit, and enforce that by having them on the same wire...

It's not that simple, what voltage and current need to held on that wire to light the LED and the camera? It's not uncommmon to find a situation where a chip doesn't technically have the right power on it's power rails, but is instead drawing power on the input ports. It's non-trivial to prove this is or isn't happening.

Re: Don't close your MacBook with a cover over the camera

#253

Post by y7 »

Closi wrote: post #188
aboutBen wrote: post #151

Earlier quoted context omitted.

If the T2 chip is compromised, then separate SoC protection is moot. The only true protection is a physical covering (like in the Lenovo) or physical kill switch (like the Purism laptops).

At that stage though all bets are off - the hackers have access to everything you have typed, all your files, all the audio from your microphones, your credit card details, those photos of you and your partner on the hard drive... Yet the camera on a laptop is the thing that we need to cover? It’s a weird security model, that’s all. Besides, on a MacBook it sounds like the webcam light is almost impossible to circumv…

For those photos of you and your partner you made the conscious decision to take them, perhaps even weighing the risks of them being compromised at some point. This is very different from a video feed being captured of you unknowingly. That goes for both the impact of such a compromise, and the feeling of the risk of being watched.

Almost impossible just means it requires lots of money/dedication, but still a T2 chip compromise is scalable and can be done remotely, which is fundamentally different from physically compromising hardware.

Re: Don't close your MacBook with a cover over the camera

#254

Post by johnhattan »

dabernathy89 wrote: post #212
duxup wrote: post #11

This seems like a pretty mild warning for folks who might stick a bulky cover on their camera and press down / pack their laptop tightly and now have wedged part of the screen open with the cover. I'm a fan of using painters tape.... pretty low profile, easily removed, stays on really well. Also the weird blue glow you get when the camera is on tells you pretty quick "Hey there's a cover on there" where sometimes wit…

It does not have to be a bulky cover. I used an extremely low profile webcam cover on my 2015 MBP for 3 years. I put a similar one on my 16" MBP, and it destroyed the screen after a couple weeks. Specifically, this is the webcam cover I was using: https://www.amazon.com/dp/B07C24NBGL/ref=cm_sw_r_sms_apa_i_T...

Ahh, thanks for the link. The webcam covers I'd seen in the past were just removable plastic stickers, and I was having a hard time visualizing what counts as "thin".

One of the photos shows them be about as thick as a credit card.

Re: Don't close your MacBook with a cover over the camera

#255

Post by aahhahahaaa »

the-pigeon wrote: post #196
alunchbox wrote: post #185

Earlier quoted context omitted.

There's a reason Zukerberg's laptop has its mic and camera tapped up. It doesn't matter what device you use unless there's a physical switch to disconnect it'll never be safe. Software can ALWAYS have zero days, just because it hasn't been exploited yet doesn't mean it can't be.

But can't you specifically wire the indicator light to always be lit if the camera has power? I don't see Apple claiming they've done that but a correct design would make the indicator light work that way and be related to software at all. Meaning you could only disable the indicator light by physically modifying the device.

This has been the case for quite some time (10 years or so). I've torn apart two Macbooks to specifically test this and the LED is enabled when the camera receives power. It's impossible to disable with software.

You can modify the Macbook of course, which is why the paranoid type will still use tape.

Some attacks I've seen will take a photo with the camera as fast as possible so you might not notice, but the light will always turn on.

Re: Don't close your MacBook with a cover over the camera

#257

Post by cgriswald »

maerF0x0 wrote: post #204
the-pigeon wrote: post #196

Earlier quoted context omitted.

But can't you specifically wire the indicator light to always be lit if the camera has power? I don't see Apple claiming they've done that but a correct design would make the indicator light work that way and be related to software at all. Meaning you could only disable the indicator light by physically modifying the device.

even then there probably should be some minimum "flash" time in that if it turns on and off faster than the LED lights up or human eyes can see then it may still take images faster than we can register? EDIT: a commenter below said "Macs newer than 4 or so years also have a feature that forces the LED to stay lit for at least 3 seconds after it has been turned on to prevent the single-frame-grab attack."

Frankly, by the time the indicator is noticed, it may be too late. Even with the LED wired in place and a 'feature' (capacitor or software?) forcing it to stay lit for 3 seconds, the damage may be done. It does, at least, let you know an attack occurred.

I really think an LED is barking up the wrong tree. A built-in hardware cover would have the same effect as the LED, and no one would have to trust it, since the camera would just be recording the back of the cover if it was hacked in stealth mode.

Re: Don't close your MacBook with a cover over the camera

#258

Post by Spooky23 »

read_if_gay_ wrote: post #172
dathinab wrote: post #108

Earlier quoted context omitted.

Doesn't matter. For many people the trust in integrated laptop cameras has been thoroughly eroded especially in case of Macs. (From my experience by interacting with people not having much tech experience, limited to Germany, maybe also limited to the social cycle(s) I interacted with.) The paradox thing is that the same people who often don't trust webcams in Apple Laptops or Apple All-In-One PCs do not bother or ev…

Why especially in Macs? Were there any particular horror stories?

Any story about Apple gets about 50x the hype because it’s a more understandable brand and set of products. The only other OEM that has any story traction is Lenovo, because China. Nobody knows what a Dell Latitude 43675b is.

There’s nothing notable or worse about the Apple issues. If anything, they are probably a lower risk than the average PC.

Re: Don't close your MacBook with a cover over the camera

#259

Post by ryandrake »

sli wrote: post #134
kelnos wrote: post #127

Earlier quoted context omitted.

I don't see how that fixes the problem; if you don't trust Apple to build in hardware safeguards around the camera indicator light, why would you trust them with a hardware switch?

A hardware switch should in theory be more easily verifiable than a software one through physical testing. Running tests on PCB traces to verify that a switch indeed works is probably a whole lot easier in general practice than decapping chips or decompiling and analyzing low level firmware or low level OS components.

But are you going to run those tests on PCB traces on your own hardware? If not, then you have to trust that your hardware is identical to whatever hardware was torn-down and tested. I suppose this is good enough unless your threat model includes someone swapping your computer enroute to you with a modified one.

Re: Don't close your MacBook with a cover over the camera

#260

Post by pantaloony »

foofoo55 wrote: post #21

Though fixed many years ago, there may be a lack of trust due to previous ability for malware to take snap shots without turning on the camera LED. https://www.theregister.com/2013/12/19/apple_isight_webcam_l...

People also do it so they don't accidentally open something that's got the camera enabled. If you're a school teacher answering questions for students in the evening you don't want to click the wrong thing and turn on video, or close the lid with something running then open it later, having forgotten, and now you're broadcasting. Stuff like that. Whether teh haxx0rs can get at the camera is irrelevant for that reason of using covers.

Personally I wish all my devices had hardware toggles for camera and mic, both. Phone included, since it's only a "phone" a small fraction of the time these days, the rest of the time it's a small Web-stuff device.

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