Despite what some fools say, you're not getting a free laptop. The Russian's real name and address is unknown, but what *IS* known is where the laptop was shipped.
Contact HP immediately with what you discovered, let them know the details. You *might* get lucky if you can give them a link to the auction and ask if you can just pay HP that amount for the laptop. (Just wild speculation on my part that they might do something like that for good will.) But, they'll probably just send you a shipping label for you to return the laptop to HP.
I really like the angle of being really honest about it with HP, and the fact that you've (you have, haven't you?) already opened the laptop before figuring out that it's a scam. Your ebay price might be more than what they can resell it for as reconditioned.