asp.net mvc - React when URL could not be Routed in MVC 4 -

There are many known exploits that look like

/ mysqladmin < / P>

Server logs, we capture the IP and add it to the firewall black list.

I would like to detect these (from a known list) in my MVC 4 app so that I can actively warn an Ops team that IP address is starting exploitation

Is there a good hook in MVC 4 to capture URL requests, which can not be routed to the controller and take further action?

There is an easy way of wildcard routing in another way.

  routes.MapRoute ("error", "{* url}", new {controller = "error", action = "notefound"});