Short for malicious software, is an umbrella term used to refer to a variety of forms of hostile or intrusive software, including computer viruses, worms, trojan horses, ransomware, spyware, adware, scareware, and other malicious programs. It can take the form of executable code, scripts, active content and other software. Malware is defined by its malicious intent, acting against the requirements of the computer user—and so does not include software that causes unintentional harm due to some deficiency.