Question about viruses in Windows 8

I've been wondering something. Considering Windows 8's main interface
sandboxes each application and the Desktop is treated like an
application, if Windows 8 was to be affected by a virus, would it exist
exclusively within the Desktop and not affect the rest of the system?

--
Silver Slimer
Wikipedia & OpenMedia Supporter

Silver Slimer wrote:
I've been wondering something. Considering Windows 8's main interface
sandboxes each application and the Desktop is treated like an
application, if Windows 8 was to be affected by a virus, would it exist
exclusively within the Desktop and not affect the rest of the system?


Your description is like an unfinished painting.
There's lots of details missing.

The kernel runs in Ring 0. The drivers run in Ring 0.
That TDSS root kit you just picked up, runs in Ring 0.
It doesn't give a rat's ass about your puny "sandbox".
It now owns the computer.

For a virus (running in Ring 3) to get you, all it needs
is an exploit that elevates it. And while Windows may throw
in a few additional accounts like TrustedInstaller, and
screw around with Regedit permissions, to make life more
difficult, I don't think this causes even a moment of
grief for a black hat. If a virus found an exploit that
left it running as a limited user, it wouldn't really
be able to go anywhere (barring sloppy changes to the
system by a user running as administrator).

No matter what sandbox you use, the attack surface of the
whole system is huge, and if there's a way in, if there
are bugs in the code, a black hat will find them. If
you write 50 million lines of code, and your software
people are any good, there are 50,000 bugs in that code
(average). And only a percentage of those have been
corrected. And some will never be corrected (too hard,
conceptual mistake etc.).

Everything has holes. When virtualization was invented,
people swore on a stack of bibles that it was bulletproof.
And then someone came out with Blue Pill.

http://en.wikipedia.org/wiki/Blue_Pill_(software)

So no matter how many clever diagrams you
draw on that white board of yours, someone
out there is laughing at you right now, while
they break into your computer.

Paul