An Unfriendly Artificial Intelligence is a Strong AI capable of causing great harm to humanity, and having goals that make it useful for the AI to do so. The AI's goals don't need to be antagonistic to humanity's goals for it to be Unfriendly, in fact almost any Strong AI not explicitly benevolent to humans is lethal. Unfriendly AI indifferent to humanity is colloquially known as Paperclip maximizer. Strong AI specifically designed to have a positive effect on humanity is called Friendly AI.