Bittrex has been subtly scamming people over the last few months, but recently they began ramping it up.
If you have assets in Bittrex, get them out ASAP.
https://www.reddit.com/r/Bittrex/comments/7oj1zp/warning_do_not_use_bittrex_scam_incoming/It also seems that scummy scammers are also trying to take advantage of Bittrex's own scamming by phishing.
On a personal note? They're holding $27 Ethereum of mine, which they won't release. Their support also begins to outright ignore you if you prove too much of a hassle (e.g. you won't give up).
Get your shit out. Now.