Type of sourcecode after post

Hi together,
I’m not sure whether it’s a problem of theme hatch….

Creating static pages works perfect (in the moment). Now I’ve created my first post and wondered about type of source code (style) at the end of the post.
It looks like links to social media pages/icons. But I haven’t any idea where to customize or hide this.
Perhaps you can have a look on this link:
https://www.thomas-blasche.de/hochzeit-eva-markus/

I have deactivated any plugins.

Thanks in advance
Thomas