Malicious Software

A program that is inserted into a system, usually covertly, with the intent of compromising the confidentiality, integrity, or availability of the victim’s data, applications, or operating system or of otherwise annoying or disrupting the victim.
SOURCE: SP 800-83
See Malicious Code. See also Malicious Applets and Malicious Logic.
SOURCE: SP 800-53; CNSSI-4009
A virus, worm, Trojan horse, or other code-based malicious entity that successfully infects a host.
SOURCE: SP 800-61

Any program used to disrupt the operations of a computer, steal sensitive information, access private computer systems, or display unwanted advertising. The main mode of malware propagation is to generate parasitic software fragments (code injection) that are inserted into an existing executable code.

SOURCE: The future of Cybersecurity in Italy: Strategic focus areas Projects and Actions to better defend our country from cyber attacks Laboratorio Nazionale di Cybersecurity CINI - Consorzio Interuniversitario Nazionale per l’Informatica