Malware

Hardware, firmware, or software that is intentionally included or inserted in a system for a harmful purpose. 

See IETF RFC 4949 Ver 2 for more information. 
 
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. 

See the following under Malware for more information: 
NIST SP 800-137  (NISTIR 7298). 
NIST SP 800-28 Version 2. 
NIST SP 800-45 Version 2. 
 
Software designed and operated by an adversary to violate the security of a computer (includes spyware, virus programs, root kits, and Trojan horses). 

See NIST SP 800-152 under Malware for more information.  
 
Software or firmware intended to perform an unauthorized process that will have adverse impact on the confidentiality, integrity, or availability of a system. A virus, worm, Trojan horse, or other code-based entity that infects a host. Spyware and some forms of adware are also examples of malicious code. 

See the following for more information: 
NIST SP 800-12 Rev. 1 under Malicious Code (NIST SP 800-53). 
NIST SP 800-171 Rev. 2 under malicious code. 
NIST SP 800-82 Rev. 2 under Malware (NIST SP 800-53). 
NIST SP 800-128 under Malicious Code (NIST SP 800-53). 
NIST SP 800-53 Rev. 4 under Malicious Code. 
NISTIR 7621 Rev. 1 under Malware (NIST SP 800-53 Rev. 4 – “Malicious Code”). 
 
A program that is written intentionally to carry out annoying or harmful actions, which includes Trojan horses, viruses, and worms. 

See NIST SP 800-28 Version 2 under Malicious Code for more information. 
 
A virus, worm, Trojan horse, or other code-based malicious entity that successfully infects a host. 

See NIST SP 800-61 Rev. 2 under Malware for more information. 
 
A computer program that is covertly placed onto a computer with the intent to compromise the privacy, accuracy, or reliability of the computer’s data, applications, or operating system. 

See  NIST SP 800-69 under Malware for more information. 
 
A program that is covertly inserted into another program with the intent to destroy data, run destructive or intrusive programs, or otherwise compromise the confidentiality, integrity, or availability of the victim’s data, applications, or operating system. 

See NIST SP 800-83 Rev. 1 under Malware for more information.