G-M

Gnutella

Program designed to allow people to "share" audio and video files with each other over a distributed network. See Napster.

Hacker

Slang name given to someone extremely knowledgeable about computers. Pejorative in some circles—but not here. See Cracker.

Hacking

The process of examining and experimenting with something, such as the telephone system or a computer, in order to find out how it works. Hacking often occurs without the owner's knowledge or permission.

Hacktivism

Form of protest that uses computer skills, mostly focusing on website defacing, to spread a message. See Web site defacing.

Hate group

An organization or collection of people who advocate violence and discrimination against another group of people. Usually motivated by religious or racial differences.

Heuristic analysis

Sometimes called rule-based or artificial intelligence analysis, it uses intelligent guesswork, which more often than not finds the solution faster than a standard algorithm. Antivirus programs use heuristic analysis to examine a file, and based on typical virus characteristics, make an educated guess as to whether a file is infected or not.

Hex editor

A program that can directly examine and modify the contents of a file or disk.

Honeypot

A phony target used to tempt hackers. Often used to keep hackers logged on to a system long enough to trace their location, or to lure a hacker into a harmless part of a network so that he or she can't get out and cause real damage . Also called a goat file.

ICQ

Popular instant messaging program.

Identity theft

Passing yourself off as another person electronically.

Information warfare

Popular term to describe hacking on an individual, commercial, and international level.

Integrity checker

A program that examines each file and calculates a numeric result based on that file's size, time, and date stamp. If the integrity checker notices that the file's size, time, or date has changed, it assumes the file may have been infected by a virus or modified by a hacker. See Checksum.

Intrusion-detection system

Program designed to detect the presence of a hacker who has already penetrated a system. Often abbreviated as IDS.

IRC

(Internet Relay Chat) A loosely structured network where people can type and send messages to each other in real time.

Java

Cross-platform programming language used to create web page applets and full-blown applications.

Keystroke recorder

A program that records keystrokes and/or mouse clicks on a computer, usually without the user's knowledge.

Linux

A free version of Unix designed for personal computers. Although Linux can be copied and distributed without restriction, many companies sell their own versions of Linux that include technical support, software, or other value-added services.

Logic bomb

A type of program, often buried within another program, that is set to go off on a certain date or by a specific event, erasing data or crashing the computer. Logic bombs are often inserted by disgruntled programmers willing to sabotage their own programs to get back at their employers.

Macro virus

A virus written using the macro programming language of a particular program. The most common macro viruses are written in WordBasic or Visual Basic for Applications, although a few macro viruses have been written in the macro programming language for WordPerfect and Lotus 1-2-3. See Visual Basic for Applications.

Master Boot Record

(MBR) The information stored on a hard disk that tells the computer how the hard disk is partitioned. Most hard disks have only one partition but can usually be divided into as many as four partitions.

Michelangelo virus

A virus that made headlines in all the major newspapers worldwide in 1992. The Michelangelo virus isn't as common as many other viruses.

MP3

Acronym that stands for Moving Picture Experts Group (MPEG) Audio Layer- 3, a file compression format for storing digital audio. See Napster and Gnutella.

Multipartite virus

A type of virus that can infect both files and boot sectors.

Mutation engine

A programming tool kit designed to help virus writers create polymorphic viruses, which can modify themselves to avoid detection by antivirus scanners. See Polymorphic virus.