Domain names drive the ubiquitous use of the Internet. Criminals and adversaries also use domain names for their enterprise. Defenders compete to remove or block such malicious domains. This paper models this competition on large, decentralized networks using a modification of Lanchester's equations for combat. The model is applied to what is known of the current state of malicious domain activity on the Internet. The approach demonstrates limitations based on the general dynamics of the model.
When taken with the economic and physical laws to which the Internet is bound, the model demonstrates that the current approach to removing malicious domain names is unsustainable and destined for obsolescence. However, there are technical, policy, and legal modifications to the current approach that would be effective, such as preemptively populating watch lists, limits on a registrant's registrations, and international cooperation. The results indicate that the defenders should not expect to eliminate or significantly reduce malicious domain name usage without employing new digital tactics and deploying new rules in the physical world.