At the moment I managed to change my password with difficulty and stop this horror. Due to the fact that the attack stopped when I changed the password, I assume that butfinex stores account passwords in clear form in its database.
Changing your password probably prompted them to kill your current session(s).
At the moment, I have UTNP and AION tokens on my accounts, but the exchange does not allow them to be exchanged for other currencies (BTC / ETH). I will try to somehow resolve the issue with the administration of bitfinex.com, but I think that SCAM
Did you look at your trade history? These are extremely thin markets on Bitfinex. A hacker probably compromised your (and other) accounts, then used the accounts to buy UTNP and AION so he could sell at very high prices and then withdraw. This is a common hacking method these days, particularly through API keys.
There's no volume for these tokens on Bitfinex. To sell AION without slippage, you may need to send them to Binance. UTNP looks pretty dead. Ethfinex does ~ 1/3 of its volume.