Virus - Attaches itself to a program and propagates copies of itself to other programs.
Worm - Program that propagates copies of itself to other computers.
Trojan Horse - Program that contains unexpected additional functionality.
Backdoor (trapdoor) - Program modification that allows unauthorized access to functionality.
Exploits - Code specific to a single vulnerability or set of vulnerabilities.
Down loaders - Program that installs other items on a machine that is under attack. Usually, a downloader is sent in an e-mail.
Kit (virus generator) - Set of tools for generating new viruses automatically.
Flooders - Used to attack networked computer systems with a large volume of traffic to carry out a denial of service (DoS) attack.
Keyloggers - Captures keystrokes on a compromised system.
Rootkit - Set of hacker tools used after attacker has broken into a computer system and gained root-level access.
Zombie - Program activated on an infected machine that is activated to launch attacks on other machines.
