How a MacBook Camera Can Spy Without Lighting Up

New submitter ttyler writes "It turns out a MacBook's built-in camera can be activated without turning on the green LED. An earlier report suggested the FBI could activate a device's camera without having the light turn on, and there was a case in the news where a woman had nude pictures taken of her without her knowledge. The new research out of Johns Hopkins University confirms both situations are possible. All it takes are a few tweaks to the camera's firmware."

Re:It's pretty simple

[weilawei]

Spoke to an Apple tech just now. It used to be, according to them. They say it isn't anymore.

It was at one time

[Anubis350]

A lens cover would not be compatible with the Apple Aesthetic (TM)

I have an external iSight [wikipedia.org] from way back, it actually does have a close-able lens

This has been known for years

[koan]

I worked for Apple, their education department had an uproar when one school district was found to spying on the students via the iSight, the light never went on.
The school admitted they set it up that way.

They were spying on them at home, I wonder how many little kids got undressed in front of their iSights while someone watched.

http://en.wikipedia.org/wiki/Robbins_v._Lower_Merion_School_District [wikipedia.org]

Re:It's pretty simple

[weilawei]

You're entirely right--you shouldn't trust hearsay. But additionally, if you look back through my post history, you'll find that I'm not in the habit of making unsubstantiated claims. The truth of the matter is that the guy (a repair tech, with long-time electronics experience, whom I trust to work on my own machines) had to go home. It's that time of the evening. But you're right, don't trust hearsay. Unfortunately, you'll have to wait on the schematics/pictures, whereas, you could probably pop open the machine yourself and take a look see if you're competent enough to understand them in the first place. I suggest you do this if you're skeptical. Heck, you might do us a favor and post them.

Re:This has been known for years

[Anonymous Coward]

"Students were particularly troubled by the momentary flickering of their webcams' green activation lights, which several students reported would periodically turn on when the camera wasn't in use, signaling that the webcam had been turned on.[8][22][24][47] Student Katerina Perech recalled: "It was just really creepy."[24] Some school officials reportedly denied that it was anything other than a technical glitch, and offered to have the laptops examined if students were concerned."

Sounds like the indicator light came on as it was supposed to, which is how they were caught spying on the kids.

Re:This has been known for years

[weilawei]

Did you read Slashdot then? Because [slashdot.org] it [slashdot.org] sure [slashdot.org] made [slashdot.org] Slashdot [slashdot.org] and was even followed by an update [slashdot.org] or [slashdot.org] three [slashdot.org].

Re:Firmware

[AmiMoJo]

Apple did actually try to fix this problem by requiring firmware updates to be encrypted. They fucked it up though and leaked the keys via the firmware update apps, so anyone could write their own battery pack malware that literally causes your laptop to catch fire.

Re:It's pretty simple

[brantondaveperson]

A sliding cover to a camera does not adhere to KISS from a user's perspective. It's actually an annoying additional step to using the camera - not to mention another moving part on a laptop that may break and/or jam. Plus it's actually less useful - if the sliding cover is open one probably still wants an LED to indicate whether or not the camera is actually active.

The idea of tying the LED to the power supply to the camera also won't work, at least for modern macbooks, because that camera sensor is in fact always active. It's also used as the ambient light sensor to automatically dim the display in low-light conditions. Of course, they could have used an additional sensor for that, but that would have increased the cost and complexity of the camera hardware.

The real issue here is much more general, which is that it should manifestly not be possible without root privileges to modify the firmware in any of the microcontrollers in a laptop (of which I'm sure there are several).

Re:It's pretty simple

[vidarlo]

If they cared even remotely enough to do that, then they would have already hardwired the indicator light to the same power source as the camera so that one couldn't be run without the other regardless of the firmware.

This is essentially what apple did, according to the report. They connected the LED to the standby signal, which normally has to be disabled to read data from the camera chip. So far, so good.

But the camera chip also has a configuration register - and one of the register options are to disable listening to the standby signal, and go ahead without caring about this signal. So it looks like the designers overlooked that option, or didn't think about it as a serious scenario.

So my impression is that apple has gone further than I've imagined to make a good design, but sadly not a bugfree design. Remember that all designs, hardware or software, may have bugs.

Re:Cams can see through black plastic

[bickerdyke]

Light from common lightsources is unpolarized, but that does NOT mean that it is not polarized, That means, it containes a mix of light polarized in every possible direction. So even if your cover lets through some specific polarization, this wil be visible and the cover would not appear opaque.

Stick with the IR wavelengths...