New in OS X: Get MacRumors Push Notifications on your Mac

Resubscribe Now Close

Software Allows Hackers to Activate MacBook Webcams Without Green Warning Light

A recently resolved criminal case shows how a man was able to hack a high school classmate's laptop in order to take nude photographs with her computer's camera without her knowledge, before attempting to use the images to extort her, reports The Washington Post.

Though Apple's FaceTime camera is designed to always illuminate the adjacent green light at the top of the screen, software has been written to separate the camera and light hardware, allowing both illegal -- and legal, the FBI has used similar software in criminal investigations -- ways.

Isight
While controlling a camera remotely has long been a source of concern to privacy advocates, conventional wisdom said there was at least no way to deactivate the warning light. New evidence indicates otherwise.

Marcus Thomas, former assistant director of the FBI’s Operational Technology Division in Quantico, said in a recent story in The Washington Post that the FBI has been able to covertly activate a computer’s camera — without triggering the light that lets users know it is recording — for several years.
A pair of students at Johns Hopkins examined Apple's webcam indicator [PDF] and discovered both how to disable the LED indicator, and a way to modify OS X's kernel to keep nefarious users from taking control of the LED. The vulnerability they described does not work on Macs built after 2008, but it is likely that similar hacks exist for newer machines.

In the older vulnerability described in the Johns Hopkins study, the software bypasses a hardware interlock that the camera uses in an attempt to ensure the indicator light illuminates whenever the camera is active. It is not known precisely which software package the defendant in the case used to compromise his classmate's computer, but the Hopkins study is the first public confirmation that Apple's camera system can be compromised.

The easiest way for users to protect themselves -- aside from standard security protocols like not downloading strange applications, or allowing untrusted people access to the computer -- is to put a small piece of tape across the camera.

Top Rated Comments

(View all)

13 months ago
(...putting pants back on...)
Rating: 127 Votes
13 months ago
Nothing looks cleaner than a small piece of tape on a 2000 dollar laptop.
Rating: 47 Votes
13 months ago
Taking my pants off.
Rating: 39 Votes
13 months ago

(...putting pants back on...)


If someone wants to see me with my pants off, that's THEIR problem.
Rating: 26 Votes
13 months ago

I would be A LOT more worried about someone accessing my HDD than my webcam. What are you people doing that you are so worried about being recorded? Do you also not go out in public?


umm..errrr...ummmm

Giggity..Giggity
Rating: 24 Votes
13 months ago
That's really disturbing
Rating: 21 Votes
13 months ago
yup; taping up my camera's now, just in case. The age of internet was nice, up 'til now. I'm not sure how all these revelations don't lead up to a massive protest overthrowing or atleast disrupting your government. It's like boiling frogs...
Rating: 19 Votes
13 months ago

I wonder if they've changed the design since 2008. I was under the impression that the LED is on the path to power the camera. In other words, they're wired together in a way that you can't send power to the camera without powering on the LED first.


But that would make it impossible for the government to spy on you without your knowledge.
Rating: 19 Votes
13 months ago
I wonder if they've changed the design since 2008. I was under the impression that the LED is on the path to power the camera. In other words, they're wired together in a way that you can't send power to the camera without powering on the LED first.
Rating: 17 Votes
13 months ago
Another case of software being a poor substitute for a hardware solution.

In the older vulnerability described in the Johns Hopkins study, the software bypasses a hardware interlock that the camera uses in an attempt to ensure the indicator light illuminates whenever the camera is active.


Per the article, they substituted their own firmware to the microprocessor responsible for the interlock. Thus calling it a hardware interlock is a bit misleading. If it really was tied to the power rail for the sensor there wouldn't be a way to bypass that. (Though if you could pulse it on and off quickly enough, someone might not notice.)

B
Rating: 12 Votes

[ Read All Comments ]