[Update 2018/12/09 4:50 PM (-8 GMT)] This is confirmed by Valve to be an Easter egg: [Original Story] The new CS:GO game mode update, Danger Zone, may have an ARG lurking inside... Or it could just be an Easter Egg. The Message in the 3rd Room In the map Blacksite, there are 3 apartments, where the 3rd one is boarded up and inaccessible from the outside. Image credit to isli25 However, there is a passage to the inside of the room via the 2nd one, and that's where things get interesting. There's a desk inside the 3rd room with several computer monitors on it. Image credit to snaileny If you stand by the desk for more than a couple of minutes, audio starts to play. It turns out there's a hidden message inside of it, and it says, "This was a triumph. I'm making a note here: HUGE SUCCESS." We'll update this thread as the community uncovers more.