Often asked, but never answered :

Here I tell you how to obtain the achievement "Putin´s Favorite Song"


- At first, in the main menu, you have to click on "View the map".

- On the next sceen, directly above "Fight" (as a part of the white house´s ground plan) you can see
"Putin´s Collusion and Ice Cream Room" - click here

- when you have done right the russian hymn will start to play and the achievements is yours.
(maybe you will hear "Katyusha", this should trigger the achievement too. Thx to @ZEROPOINTBRUH)

Congratulations, folks, you´ve done it ! (^-^)