Email worm modeling and defense

Email worms constitute one of the major Internet security problems. In this paper, we present an email worm model that accounts for the behaviors of email users by considering email checking time and the probability of opening email attachments. Email worms spread over a logical network defined by email address relationship, which plays an important role in determining the spreading dynamics of an email worm. Our observations suggest that the node degrees of an email network are heavy-tailed distributed. We compare email worm propagation on three topologies: power law, small world and random graph topologies; and then study how the topology affects immunization defense on email worms. The impact of the power law topology on the spread of email worms is mixed: email worms spread more quickly on a power law topology than on a small world topology or a random graph topology, but immunization defense is more effective on a power law topology than on the other two