Hi,

Please make sure your System is not infected. I highly suggest you to download MBAM from https://www.malwarebytes.org/
Once downloaded you could activate the real time scanner, but for a quick scan just don't enable this trial.

Also in case you have a mobile phone Android/IOS download a Authenticator from blizzard to max security.
If your using a password for alot of the same things and lets say a Forum would be compromised and data is leaked with passwords this might be a problem.

I hope you sort out the problems,

Vayku