Update: Just now, it happened again. After waking the computer from suspension, it was sluggish. I pressed Ctrl-Alt-Delete, but this time, it froze everything right away, the mouse and keyboard had power, but did not do anything. After a while, the screen went black, and the computer was unresponsive and forced me to press the manual reset once again. It seems it is related to suspension, somehow.
Last night I had a scary event. I woke my computer out of suspended mode, and found that it reacted sluggishly. Changing tabs took several seconds, there was a distinct delay to everything.
So I pressed Ctrl-Alt-Delete to bring up the task manager. I clicked the tab to sort the CPU intensive processes to the top, and saw that it was something like
nvstreamnv.exe slurping up a gig and more of memory. Then all of a sudden I lost control of mouse and keyboard! The mouse had no power, the infrared light was not glowing. I think the keyboard lights were still on, but no keys worked. After a while, all my Firefox windows were shut down at once. Later I got the message about restoring the session did not work as expected, so it seemed like an unusual shutdown.
At this point I pressed the reset button and restarted in failsafe mode.
I fiddled around in there, checked logs, and found nothing of significance (but then I don't know what to look for). I did turn off the "accept remote help" option, which was mysteriously turned on. I could not run any program in failsafe mode, as I thought I could, so I rebooted and ran my antivirus, which found nothing.
Since my antivirus (F-Secure) had been acting strange just the day before, this added to my paranoia. It had gone offline, giving me the windows warning thing "No antivirus is active" or whatnot, and then asking me to reboot. So I went to www.microsoft.com and found some online downloadable scanner, which reported no viruses. I also went to www.kapersky.com and downloaded a scannar, which reported no viruses or malware.
Feeling a bit more reassured, I am still worried. Due to a game I had played earlier, I had switched from my regular firewall to the Windows Firewall, which might have left me vulnerable. This was done via msconfig, turning off the service at the time in a trial and error fashion.
My question is, what could account for losing control of keyboard and mouse like that? The "nvstream.exe" seems to be connected to my NVIDIA software, as near as I can tell, and it looks like someone was remote controlling my computer, using my video card to send visuals? Should I be worried, do something else? Could some malware/trojan be still in my computer, even though the antivirus scans found nothing?