Malicious Code<p>Malicious code is any code in any part of a software system or script that is intended to cause undesired effects, security breaches, or damage to a system. Such codes actually gain unauthorised access to system resources or tricks a user into executing other malicious logic. Malicious code describes a broad category of system security terms that includes attack scripts, viruses, worms, Trojan horses, backdoors, and malicious active content.</p>