The glossary below contains many of the terms you will find in common use throughout our website. Please refer to this list to find definitions of terms and answers to other Internet security-related questions.


A type of non-parasitic malicious code that has unexpected and malicious consequences. Trojans represent themselves as something other than what they truly are. The Trojan may even perform the functions it initially indicates when executed, but will also carry out its malicious actions. Also called Trojan horse.