Website was hacked

Hello wordpress community,
Today my website was hacked by unknown persons.
What i found at that morning into my website:
1. Title was changed to following: +ADw-/title+AD4-Hacked By Alarg53+ADw-DIV style+AD0AIg-DISPLAY: none+ACIAPgA8-xmp+AD4-
2. My website 3 cloumns layout was removed, missing categories “Recent posts” and “Random posts”.
And everywhere D”D?D?D°??D????? D′D??? D?D·D±?€D°D?D?D?D3D? such signs.

Also there is a lot of websites with such titles.
How to fix it?

• This topic was modified 7 years, 11 months ago by Steven Stern (sterndata). Reason: moved from "hacks" to "troubleshooting"