Glossary

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

Trojan horse

Trojan horses are impostors. The files claim to be desirable programs, but they are malicious. A very important distinction from true viruses is that they do not replicate themselves, as viruses do. Trojan horses contain a malicious code which, when triggered, causes loss or theft of data. For a Trojan horse to spread, you must invite these programs onto your computer; for example, by opening an email attachment. Trojan horses are also known to create a back door on a computer. The back door gives another user access to a system, and possibly allows confidential or personal information to be compromised. Unlike viruses and worms, Trojan horses neither reproduce by infecting other files, nor do they self-replicate.

A program that claims to be a desirable program but is malicious. A very important distinction from true viruses is that they do not replicate themselves, as viruses do. Trojan horses contain malicious code, which causes loss or theft of data. For a Trojan horse to spread, you must invite these programs onto your computer; for example, by opening an email attachment. Trojan horses are also known to create a backdoor on a computer. The backdoor gives another user access to a system and possibly allows confidential or personal information to be compromised. Unlike viruses and worms, Trojan horses do not reproduce by infecting other files, nor do they self-replicate.