Malicious+software

=Malicious software= Software designed specifically to damage or disrupt a system, such as a virus or a Trojan horse.

Malicious code is the term used to describe 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. Malicious code describes a broad category of system security terms that includes attack scripts, viruses, worms, Trojan horses, backdoors, and malicious active content. (//from Webopedia//)