If a scenario like that was true we shouldn’t be here in the first place. Assuming that there is an advanced civilization out there in a killing spree all they’d have to do is launch a legion of probes in the outskirts of the galaxy and once they find sentient life unleash a biological weapon and eradicate it once and for all. They don’t have to find us by listening to radio waves. They could just look for planets that could support life, same as we do with our Kepler mission. Only they could have spotted Earth hundreds of thousands of years ago, so no chance for humanity to evolve in our current state at all.