There isn’t an “aimbot scanner” for Halo, but if you want to check if anybody is playing with an aimbot in Halo CE(Custom Edition, NOT Combat Evolved. Custom Edition is a downloadable game exactly like Halo, except for the fact that you can play custom maps that you or other people have made) you can download a program called “Sightjack”, which allows you to see what everyone sees and if you see them moving around very fast without looking anywhere else, then they’re using an aimbot.
When you’re looking for tools like an aimbot scanner, you might want to explore resources that provide detailed insights into these kinds of software, a good place to start is valorant aimbot. While it focuses on Valorant, it offers useful information on aimbots that might give you an idea of where to look for similar tools for Halo.