Excellent instruction, thanks! But:
After such a horrible loss, I would suggest that you up your security and segregate either a computer, or an operating system, that is not used for general tasks or whatnot, just for money, and lock it down tight, strong password, and don't install anything more than the browser and cryptocoin wallets you need.
But what if bittrex himself is infected??
And I think this 7BTC was stolen by bittrex, Not by malware bot.