attack, n. an attempt to steal, destroy, or alter data off a computer or network.

black hat, n. an unethical hacker who breaks into computer systems for personal gain.

botnet, n. a network of computers controlled by cybercriminals using a malicious program.

DoS attack, n. a Denial-of-Service (DoS) attack is designed to obstruct or stop the normal functioning of a Web site, server, or network resource. One way in which hackers do this is to flood the server with more requests than it can handle.

DDoS, n. a distributed Denial of Service Attack (DDos) is a DoS attack that uses multiple machines. Hackers will often use one “master” machine to coordinate with other “zombie” machines.

drive-by-download, v. a drive-by-download is a malicious download of malware that happens invisibly after you visit a Web site that has been compromised by a hacker.

fuzzing, v. when hackers input lots of random data — or fuzz — in an attempt to make a system crash. Used by hackers to look for vulnerabilities in code.

keylogger, n. a keylogger records everything a user types, including passwords and credit card details.

malware, n. a term used for all software that is intended to be harmful or perform unauthorized actions.

phishing, n. the attempt to acquire credit card details, passwords and personal details by tricking individuals into entering personal information on fake Web sites that closely resemble legitimate ones.

rootkit, n. the programs a hacker uses to avoid detection while gaining unauthorized access to a computer.

social engineering, v. to manipulate people into sharing private/confidential information.

spear-phishing, n. a type of phishing targeting a specific individual or department within an organization.

spyware, n. a type of malware that harvests users’ confidential data, e-mail addresses and browsing habits and forwards the information without users’ consent to a third party.

Trojan horses, n. malware that appears to be legitimate but that when launched can do something harmful such as steal passwords or give a hacker access to the network.

virus, n. a computer program that can replicate itself and spread from computer to computer, corrupting files or stealing information.

white hat, n. an ethical hacker who breaks into a system to expose security flaws, usually at the request of its owner.

worm, n. like viruses, computer worms replicate and harm and they often rely on security failures to enter a computer network.

zero day attack, n. a cyber attack that exploits a vulnerability in a computer application which was previously unknown.