Most webcams
have a warning light that indicates when they’re active, but it’s possible for
malware to disable this important privacy feature on older Mac computers,
according to research from Johns Hopkins University (JHU) in Baltimore.
In right
contradiction to every other webcams I have ever met, own and used, this is a new direction of invention.
JHU Assistant
Research Professor Stephen Checkoway and graduate student Matthew Brocker
investigated the hardware design of the first-generation iSight webcam model
installed in Apple’s iMac and MacBook computers released before 2008 and found
that its firmware could easily be modified to disable the indicator LED.
At
the hardware level, the LED is directly attached to the webcam’s image sensor,
particularly its STANDBY pin. When the STANDBY signal is active the LED is off
and when not active, the LED is on, the JHU researchers said in a recently
released paper.
In order to
disable the LED, the researchers had to find a way to activate STANDBY, but
also configure the image sensor to ignore it because when STANDBY becomes
active the image sensor output automatically gets disabled, so the webcam
cannot be used to capture images. Spies
To achieve
this the researchers created a modified version of the iSight firmware and then
reprogrammed the camera with it, using a method that involves sending
vendor-specic USB device requests from the host OS. They found that this
operation doesn’t require root privileges and can be done from a process
started by a regular user account.
The JHU
researchers created a proof-of-concept application called iSeeYou that detects
whether an iSight webcam is installed, reprograms it with the modified firmware
and then allows the user to start the camera and disable the LED. When the
iSeeYou application is stopped, the camera is reprogrammed with the original,
unaltered firmware.
In addition
to spying on users without them knowing, the ability to easily reprogram the
iSight camera could also allow malware to escape from an operating system that
runs inside a virtual machine, the researchers said.
To
demonstrate, this they reprogrammed the camera from a guest OS running inside
VirtualBox—a virtual machine program—to act as an Apple USB keyboard. This allowed
them to send key presses that transferred the keyboard’s ownership from the
guest OS to the host OS and then executed shell commands on the host OS.
The JHU
researchers didn’t only document the iSight weakness, but also proposed
defenses, both at the software and hardware levels, against attacks that might
try to exploit it. They built a Mac OS X kernel extension called iSightDefender
that blocks specific USB device requests that could be used to load rogue
firmware from being sent to the camera.
This kernel
extension raises the bar for attackers because they would need root access to
bypass it. However, the most comprehensive defense would be to change the
hardware design of the camera so that the LED cannot be disabled by software,
the researchers said.
Several
proposals on how that could be achieved, as well as recommendations on how to
secure the firmware update process, are presented in the paper.
The
researchers said they’ve sent the report and their proof-of-concept code to
Apple, but they haven’t been informed about any possible mitigation plans.
Apple did
not immediately respond to a request for comment.
There’s been
a rise in recent years in the number of cases in which hackers spied on
victims—primarily women—in their bedrooms and other private settings though
their webcams.
One
recent case of “sextortion”—extortion using illegally obtained nude photographs
of victims—involved 19-year-old Cassidy Wolf, the winner of the 2013 Miss Teen
USA title.
In
September, the FBI arrested a 19-year-old man named Jared Abrahams from
Temecula, California, on charges that he hacked into the social media accounts
of several women, including Wolf, and took nude photographs of them by remotely
controlling their webcams. He then allegedly contacted the victims and
threatened to post the pictures on their social media profiles unless they sent
him more nude photos and videos or did what he demanded for five minutes in
Skype video chats.
Wolf said
in media interviews that she had no idea someone was watching her through
her webcam because the camera’s light didn’t go on.
There are
hackers who bundle remote administration tools (RATs) that can record video and
sound from webcams with malware, the JHU researchers said in their paper. Based
on discussion threads on hacker forums many of these individuals, who are known
as “ratters,” are interested in the ability to disable the webcam LEDs, but do
not think it is possible, they said.
This new
research shows that it is possible, at least on some computers.
”In this
paper, we have examined only a single generation of webcams produced by a
single manufacturer,” the researchers said. “In future work, we plan to expand
the scope of our investigation to include newer Apple webcams (such as their
most recent high-definition FaceTime cameras) as well as webcams installed in
other popular laptop brands.”
Security
experts have advised users in the past to cover their webcams when not in use
in order to avoid being spied on in case their computers get compromised.
Having a webcam of such in our days will make it more easier to capture the "target" without him/her ever knowing.
I raise my
thumb Up for this guys...Cheers
No comments:
Post a Comment