Malicious Programs

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.

Auto-rooter -Malicious hacker tools used to break into new machines remotely.

Kit (virus generator) - Set of tools for generating new viruses automatically.

Spammer programs - Used to send large volumes of unwanted e-mail.

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.