The increased use of the World Wide Web and JavaScript as a scripting language for Web pages have
made JavaScript a popular attack vector for infecting users' machines with malware. Additionally,
attackers often obfuscate their code to avoid detection, which heightens the challenge and complexity of
automated defense systems. We present two analyses of malicious scripts and suggest how they could be
extended into intrusion detection systems. For our analyses we use a sample of deobfuscated malicious
and benign scripts collected from actual Web sites.