Intended for system administrators, this security guide characterizes the latest wave of malicious code attacks being used to invade commercial computer systems based on Windows and UNIX worms, mobile code on the web, backdoors, Trojan horses, and kernel-mode rootkits recommends defenses to protect systems against each type of attack, and provides instructions for building an experimental network to analyze malicious code and the associated defenses. Annotation ©2004 Book News, Inc., Portland, OR (booknews.com)