I don't think its Poloniex either, and Bittrex won't comment if its there's or not.. but by now its probably too late. Just hope no one else falls for this again.
I contacted poloniex and bittrex immediately.
Poloniex very quickly told me it wasn't their address.
Bittrex were very unhelpful and eventually told me:
Your request (...) has been solved. To reopen this request, reply to this email.
Bill
Bill (Bittrex)
Jun 24, 21:02
Hi Chris,
Could you encourage that user to contact the appropriate authorities to conduct an investigation?
Thanks,
Bill
I think when they say it "has been solved" they mean it "hasn't been solved but please go away". They never would even tell me whether they owned the address the stolen coins were sent to or not.
I hadn't tried their customer support until then, but this was all the experience I needed to know that I should withdraw my balances ASAP.