Depends on what they say.
"We're a peaceful communal species that is hyper advanced and will share our knowledge with you if you disarm yourselves, form a world goverment,mix together into one race, give up all propertt , obey the state, and listen to you're friendly neighborhood merchant! If you don't we're gonna whipe this place clean and spare only those enlighten enough to do exactly what the media tells them to do!"
It's fake, and or they're evil.
"We have come to liberate your world from the tiny cabal of monsters who rule over you, and hopefully you will be able to recover and become the great people we once traded with in the past!"
They're probably real, and/or good. But then every nuke is gonna get launched at once because the elites are gonna panic.
So we're all gonna die either way.