Viruses against humans, viruses against livestock as an attack against humanity's food chin, plant diseases, half of humanity feeds on three plants maize, wheat, rice. Attacks against infrastructure like water, internet, electricity.

Which one of these would it be? All of them in parallel? Or something we wouldn't think of. If I were to play chess against Magnus Carlsen, I wouldn't know with which piece he will checkmate me, but I know that I am going to lose.