Malware "Ecology" Viewed as Ecological Succession: Historical Trends and   Future Prospects
  The development and evolution of malware including computer viruses, worms, and trojan horses, is shown to be closely analogous to the process of community succession long recognized in ecology. In particular, both changes in the overall environment by external disturbances, as well as, feedback effects from malware competition and antivirus coevolution have driven community succession and the development of different types of malware with varying modes of transmission and adaptability. 
Reginald D. Smith
cs.CR q-bio.PE