Book excerpt: Written by a pioneer in the field, this updated and expanded revision covers all aspects of computer viruses. New results include: analysis of the epidemiology of computer viruses, new forms of virus evolution that will render most current safeguards useless, strategy and tactics in virus defenses, assessment of synergistic effects in attack and defense. Features new chapters on LANs, international and `good' viruses. Software includes a virus scanner, a password generator and checker, an `integrity' shell to test systems and much more. Packed with historical facts, anecdotes and authentic examples.