Unaouthrized acces from unknow location.

Greetings,
I've got quite a problem.
Today, at the middle of the night, I've received spam like amount of mails from Warmane with authorization codes (I've seen it on my smartphone notifications).
All of them from country I havent ever been and don't know anyone from there (I've checked by IP adress in my account page).

I log to Warmane only by my personal PC, standing in my home, connected to the network with hardware firewall and having latest NOD32 up to date. Never logged into site or game from other places. Never shared it with anyone (I'm solo player).

I have a question - how it is possible that someone knows my login and password to be able to pop up auth request? What am I missing? How my account data leaked?

EDIT: Is there a way to change in-game login? I've remember that there was such option on old site (or was it forum name?), but it is missing now. It would be great change for extra safety.