Attacks from AWS servers
What's the point? The traffic would still be spent. You can look up the allocations on this AS and block it with e.g. iptables.
So how and where do I do this?
By the way If you don't even know how to block an ip using iptables, I suspect your server setup may be insecure in many ways. Get some professional help. Don't get me wrong, this is just a friendly advice.