Hi ,
I’m messaging Epic through back channels to see if I can get an answer for you, there have been a few reports of this from other users today as well.
In the meantime please read through this Security bulletin for more details on how to protect yourself from further issues:
http://launcherhelp.epicgames.com/customer/en/portal/articles/2921261-account-security-bulletin
Personally if I was you I would immediately change your password and turn on 2-factor authentication to make sure they can’t get in. You can do this by hovering over your name at the top right of this page and select “Personal”, then go to Password & Security and scroll down to the bottom.