This is a difficult one to help with and that may explain the lack of replies. If as you claim your system was functioning normally before this happened and that you didn't install anything
out of the ordinary or reconfigure anything which might have caused this, then it's likely to be a hardware issue. I can't imagine you picking up anything nasty from browsing torrent sites, unless you were running x server as root...?
Does the unresponsive input occur everywhere
? In virtual terminals, web browsers, text editors? i.e. if you kill the x server and type in a virtual terminal, does it respond normally? Is the whole system unresponsive or just text input?
If it is, then next step in my opinion would be to quickly attempt eliminate the hardware and the best way to do that, at least partially, is to boot from a live system:
If the live system has the same problem, then it's possibly a hardware problem.