4 ms·

Would this prevent someone swapping the physical LED out with something that would take the voltage but try to hide the light? Maybe like a IR led? Or even some

Would this prevent someone swapping the physical LED out with something that would take the voltage but try to hide the light? Maybe like a IR led? Or even some circuit that can be toggled to act as a resistor? I guess an evil maid/supply side attack is much less likely than just hacking the software but still...

wtallis 2y ago
I'm not sure about iPads, but on my MacBook Air the camera/microphone indicator light is not a discrete LED but drawn using pixels on the screen.
- saagarjha 2y ago
  It’s not a physical LED, it’s essentially a piece of software isolated from the OS that draws to the screen
  - trollied 2y ago
    Wow. Do you have a reference for that?
    - klausa 2y ago
      ...the very article you're commenting about is exactly about this?
- nebula8804 2y ago
  Do you have a Macbook with that center gap in the screen? Because I notice different behavior on my 2023 Macbook Pro vs my iPhone 13 Mini. On the iPhone if you observe closely, it is drawing a green circle on the screen area where you normally see portions of your OS or app. It starts with a tiny circle and grows until it becomes a certain size. When you close the camera app, the circle turns orange and shrinks until it disappears. On the Macbook, it is a bright green circle that just turns on like an LED and is located in the cut off portion of the screen that has nothing software related in it. When the camera using app is close the circle just disappears like an LED turning off.
  - wtallis 2y ago
    Ok, apparently I just don't use the camera very often on my Mac. It looks like an app using the camera triggers a discrete LED in the notch, but an app using only the microphone triggers an indicator in the menu bar (which becomes a green dot of pixels in the corner of the screen when in a full-screen app where the menu bar is hidden).
klausa 2y ago
Swapping out physical LEDs out of an OLED screen might be difficult.
- echoangle 2y ago
  You could try to break the individual LEDs. That might be detectable by the display driver but I’m not sure if that is really checked.
  - klausa 2y ago
    I would presume user would notice a segment of their display becoming non-functional; but maybe I'm just built different.
    - echoangle 2y ago
      Well the indicator is shown on a segment of the display which is otherwise black. And since it’s OLED, you don’t break the backlight but the pixels itself. How would you notice just the pixels used for the indicator being broken? You would only notice when you expect the indicator to be shown but it isn’t, but that’s the same as in the scenario of the top comment.
      - klausa 2y ago
        >Well the indicator is shown on a segment of the display which is otherwise black. It is not. What gave you that idea?
        echoangle 2y ago
        I was thinking of the iPhone where it is shown between camera and depth sensor. Where is it on the iPad?
- nebula8804 2y ago
  Seems like some products use software based indicator where it draws directly to the OLED and others use physical LED? Ive tested iPhone 13 Mini which has software light and 2023 Macbook Pro seems to have a traditional LED. They seem to operate differently as I explained in my other comment.
echoangle 2y ago
That’s impossible to prevent. If you have that level of hardware access and sophistication of modifying the device, you have already lost if you leave the computer alone. The only way to prevent this in any way would be a light sensor on the other side of the case which you could use to check the Indicator when the laptop is closed. But if you can’t trust your hardware to that level, there are thousands of other attacks you can do.
- nebula8804 2y ago
  Well you have a point and I was thinking about it. Only thing I can think of is eliminating the LED in favor of software (which is what they have done in some products) or putting silicon in the LED to verify it. Ugh have we now reached the point where we have to put some crypto in everything including our LEDs?
  - echoangle 2y ago
    I think that’s just a too advanced threat you want to handle. If you are facing such an opponent, you shouldn’t let your hardware out of your hands at any time. You can probably replace the battery by a smaller model and put a keylogger in the remaining space. There’s just no way to prevent hardware modification without using tamper evident seals on all openings, and even that probably isn’t 100% safe.
maven29 2y ago
Point an illegal high wattage laser pointer at it?
m463 2y ago
how about swapping it out with a small... camera?

wtallis 2y ago

I'm not sure about iPads, but on my MacBook Air the camera/microphone indicator light is not a discrete LED but drawn using pixels on the screen.

saagarjha 2y ago
It’s not a physical LED, it’s essentially a piece of software isolated from the OS that draws to the screen
- trollied 2y ago
  Wow. Do you have a reference for that?
  - klausa 2y ago
    ...the very article you're commenting about is exactly about this?
nebula8804 2y ago
Do you have a Macbook with that center gap in the screen? Because I notice different behavior on my 2023 Macbook Pro vs my iPhone 13 Mini. On the iPhone if you observe closely, it is drawing a green circle on the screen area where you normally see portions of your OS or app. It starts with a tiny circle and grows until it becomes a certain size. When you close the camera app, the circle turns orange and shrinks until it disappears. On the Macbook, it is a bright green circle that just turns on like an LED and is located in the cut off portion of the screen that has nothing software related in it. When the camera using app is close the circle just disappears like an LED turning off.
- wtallis 2y ago
  Ok, apparently I just don't use the camera very often on my Mac. It looks like an app using the camera triggers a discrete LED in the notch, but an app using only the microphone triggers an indicator in the menu bar (which becomes a green dot of pixels in the corner of the screen when in a full-screen app where the menu bar is hidden).

klausa 2y ago

Swapping out physical LEDs out of an OLED screen might be difficult.

echoangle 2y ago
You could try to break the individual LEDs. That might be detectable by the display driver but I’m not sure if that is really checked.
- klausa 2y ago
  I would presume user would notice a segment of their display becoming non-functional; but maybe I'm just built different.
  - echoangle 2y ago
    Well the indicator is shown on a segment of the display which is otherwise black. And since it’s OLED, you don’t break the backlight but the pixels itself. How would you notice just the pixels used for the indicator being broken? You would only notice when you expect the indicator to be shown but it isn’t, but that’s the same as in the scenario of the top comment.
    - klausa 2y ago
      >Well the indicator is shown on a segment of the display which is otherwise black. It is not. What gave you that idea?
      - echoangle 2y ago
        I was thinking of the iPhone where it is shown between camera and depth sensor. Where is it on the iPad?
nebula8804 2y ago
Seems like some products use software based indicator where it draws directly to the OLED and others use physical LED? Ive tested iPhone 13 Mini which has software light and 2023 Macbook Pro seems to have a traditional LED. They seem to operate differently as I explained in my other comment.

echoangle 2y ago

That’s impossible to prevent. If you have that level of hardware access and sophistication of modifying the device, you have already lost if you leave the computer alone. The only way to prevent this in any way would be a light sensor on the other side of the case which you could use to check the Indicator when the laptop is closed. But if you can’t trust your hardware to that level, there are thousands of other attacks you can do.

nebula8804 2y ago
Well you have a point and I was thinking about it. Only thing I can think of is eliminating the LED in favor of software (which is what they have done in some products) or putting silicon in the LED to verify it. Ugh have we now reached the point where we have to put some crypto in everything including our LEDs?
- echoangle 2y ago
  I think that’s just a too advanced threat you want to handle. If you are facing such an opponent, you shouldn’t let your hardware out of your hands at any time. You can probably replace the battery by a smaller model and put a keylogger in the remaining space. There’s just no way to prevent hardware modification without using tamper evident seals on all openings, and even that probably isn’t 100% safe.

maven29 2y ago

Point an illegal high wattage laser pointer at it?

m463 2y ago

how about swapping it out with a small... camera?