Autonomous Agents For Intrusion Detection

AAFID(tm) is a distributed monitoring and intrusion detection system
that employs small stand-alone programs (Agents) to perform monitoring
functions in the hosts of a network. AAFID uses a hierarchical
structure to collect the information produced by each agent, by each
host, and by each set of hosts, to be able to detect suspicious
activity.

WWW: http://www.cerias.purdue.edu/projects/aafid.html