sry i have trouble actually beliving this, you just lost 500k$ and you have a problem with turning off your work pc? seriously?
personally i think this is a troll, but if not, then you did everything in your power to lose that money, short of posting your wallet.dat on forum for "safekeeping" and it most deffinetly was not a hack from far away, physical attack vectors are always 100X easier
if you dont know how to protect your assets they will find a new owner, that applies in both bitcoin and offline, someone having 500k$ under their bed and telling their friends about it will lose it very quickly too
I never said I can't turn off the computer. I said I can't turn it off at this very moment. I have to backup whatever important stuff I have left on it. I store in encrypted format password to some banking and other info. At this point I have to assume all that is compromised and eventually I have to go through the laborious task of changing everything! There are many things on my to do list.
I am not a troll.