A Hacker is somebody who finds weaknesses in a computer or computer network and exploits them through a process called penetration or penetration testing (depending on the motive). Hackers may be motivated by a multitude of reasons such as profit, protest, challenge, or to aid security by pointing out vulnerabilities.[1] The subculture that has evolved around hackers is often referred to as the computer underground and is now a known community.

Bruce Sterling traces part of the roots of the computer underground to the Yippies, a 1960s counterculture movement which published the Technological Assistance Program (TAP) newsletter.TAP was a phone phreaking newsletter that taught the techniques necessary for the unauthorized exploration of the phone network. Many people from the phreaking community are also active in the hacking community even today, and vice versa.

Several subgroups of the computer underground with different attitudes use different terms to demarcate themselves from each other, or try to exclude some specific group with which they do not agree. Below is a list of the different types of hackers that dwell in the computer underworld.

White hat

A “white hat hacker” (also known as an ethical hacker) breaks security for non-malicious reasons, perhaps to test their own personal security system, or while working for a company that needs intensive security assurance. Many hackers in this classification perform penetration tests and vulnerability assessments within a contractual agreement. Some black hat hackers will transfer over into becoming a white hat hacker after they get caught illegally breaking into a system whose company sees value in having somebody with this level of knowledge work for them.

Black hat

A “black hat hacker” (also known as a cracker) is a hacker who violates computer security with malicious intent or for personal gain.[2] Black hat hackers form the stereotypical illegal hacking groups often portrayed in pop culture, and are “the epitome of all that the public fears in a computer criminal”.[3] Black hat hackers break into secure networks to destroy data or make the network unusable for those who are authorized to use the network. They choose their targets using a two-pronged process known as the “pre-hacking stage”.

Part 1: Targeting

The hacker determines what network to break into during this phase. The target may be of particular interest to the hacker, either politically or personally, or it may be picked at random. Next, they will port scan a network to determine if it is vulnerable to attacks, which is just testing all ports on a host machine for a response. Open ports—those that do respond—will allow a hacker to access the system.

Part 2: Research and Information Gathering

It is in this stage that the hacker will visit or contact the target in some way in hopes of finding out vital information that will help them access the system. The main way that hackers get desired results from this stage is from “social engineering”, which will be explained below. Aside from social engineering, hackers can also use a technique called “dumpster diving”. Dumpster diving is when a hacker will literally search through users’ garbage in hopes of finding documents that have been thrown away, which may contain information a hacker can use directly or indirectly, to help them gain access to a network.

Part 3: Finishing The Attack

This is the stage when the hacker will invade the preliminary target that he/she was planning to attack or steal. Many “hackers” will be caught after this point, lured in or grabbed by any data also known as a honeypot (a trap set up by computer security personnel).

Part 3: “crackerbots” Bot crackers, or crackerbots, will try password and username combinations t o gain access to a target’s account.

Grey hat

A “grey hat hacker” is a combination of a black hat and a white hat. These hackers may hack into a computer system to notify the administrator that their system is vulnerable and then offer to repair their system for a small fee. This is both a white and black hat act since they are doing it for a good purpose but still demanding personal gain and without signed permission from the company, hence the term “grey hat”.

Blue hat

A “blue hat hacker” is someone who is used to bug test a system prior to its launch, looking for exploits so they can be closed. Microsoft also uses the term BlueHat to represent a series of security briefing events.

Neophyte

A “neophyte” is a new hacker that is making an honest effort to enter the world of hacking. Not to be confused with script kiddies (described below), neophytes already have a strong understanding of how computers, networks, and programs work. Neophytes understand that it takes will, patience, and learning before they can truly claim them-self to a classification such as white hat, black hat, grey hat, or blue hat.

Script kiddie

A “script kiddie” (aka skiddie) is a person who breaks into computer systems using tools with no understanding or care of how they work. They lack technical backgrounds and effective technique as opposed to the majority of hackers with substantial post-secondary education in IT security from a college/university, or equivalent training. They usually don’t make it very far and give up as soon as something doesn’t go as planned, hence the term script kiddie (i.e. script, a prearranged plan or set of activities)(i.e. kid, child—an individual lacking knowledge and experience, immature).

Hacktivist

A hacktivist is a hacker regardless of classification who utilizes technology vulnerabilities to announce a social, ideological, religious, or political message. In general, most hacktivism involves website defacement or denial-of-service attacks.

Elite hacker

A social status used to describe the most skilled hackers regardless of classification. Newly discovered exploits will circulate among these hackers. Elite groups such as Masters of Deception conferred a kind of credibility on their members.