Honours Thesis

Early Bird: Catching worms while sysadmins sleep

Andrew Hill, B.Sc., B.Sc. (Math. & Comp. Sci.)

School of Computer Science
The University of Adelaide
South Australia

Supervisors: Mr. Kevin Maciunas and Dr. Cheryl Pope

November 2, 2003


Abstract

This honours thesis demonstrates the need for an automated, anomaly-based Internet worm detection system that is effective at identifying Internet worm packets with a low false-positive rate.

The theory of general Discrete Symbol Hidden Markov Models and the theory of the equivalent on-line models is discussed, and the general structure of Hidden Markov Models is related to the problem of identifying Internet worm packets in a sequence of normal network packets.

The effectiveness of various on-line Hidden Markov Model configurations in detecting Sapphire Internet worm packets in a sequence of normal UDP packets is evaluated, demonstrating that Hidden Markov Models can be successfully used as the basis of an automated, anomaly-based Internet worm detection system.

Download the thesis in PDF format.

Download the Hidden Markov Model source code.