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Hacker (computer security)

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hacker is a person who breaks into computers and computer networks for profit, as protest, or sometimes by the motivation of the challenge.[1] The subculture that has evolved around hackers is often referred to as the computer underground but is now an open community.[2]

Other definitions of the word hacker exist that are not related to computer security. They are subject to the long standing hacker definition controversy about the true meaning of hacker. In this controversy, the term hacker is reclaimed by computer programmers who argue that someone breaking into computers is better called cracker,[3] not making a difference between computer criminals (“black hats”) and computer security experts (“white hats”). Some white hat hackers claim that they also deserve the title hacker, and that only black hats should be called crackers.




In today’s society understanding the term “hacker” is complicated because it has many different definitions. The term can be traced back to MIT (Massachusetts Institute Technology). MIT was the first institution to offer a course in computer programming and computer science and it is here in 1960 where a group of MIT students taking a lab on artificial intelligence first coined this word. These students called themselves hackers because they were able to take programs and have them perform actions not intended for that program. “The term was developed on the basis of a practical joke and feeling of excitement because the team member would “hack away” at the keyboard hours at a time.” (Moore R., 2006).[4]

Hacking developed alongside phone phreaking, a term referred to exploration of the phone network without authorization, and there has often been overlap between both technology and participants.[citation needed] One of the first hacks was accomplished by Joe Engressia also known as The Whistler. Engressia is known as the grandfather of phreaking. His hacking technique was that he could perfectly whistle a tone into a phone and make a free call.[5] 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.[6] Other sources of early 1970s hacker culture can be traced towards more beneficial forms of hacking, including MIT labs or theHomebrew Computer Club, which later resulted in such things as early personal computers or the open source movement.

[edit]Artifacts and customs

The computer underground[1] is heavily dependent technology. It has produced its own slang and various forms of unusual alphabet use, for example 1337speak. Writing programs and performing other activities to support these views is referred to as hacktivism. Some go as far as seeing illegal cracking ethically justified for this goal; a common form is website defacement. The computer underground is frequently compared to the Wild West.[7] It is common among hackers to use aliases for the purpose of concealing identity, rather than revealing their real names.

[edit]Hacker groups and conventions

Main articles: Hacker conference and Hacker group

The computer underground is supported by regular real-world gatherings called hacker conventions or “hacker cons”. These draw many people every year including SummerCon (Summer), DEF CON,HoHoCon (Christmas), ShmooCon (February), BlackHat, Hacker Halted, and H.O.P.E..[citation needed] In the early 1980s Hacker Groups became popular, Hacker groups provided access to information and resources, and a place to learn from other members. Hackers could also gain credibility by being affiliated with an elite group.[8]

[edit]Hacker attitudes

Several subgroups of the computer underground with different attitudes and aims use different terms to demarcate themselves from each other, or try to exclude some specific group with which they do not agree. Eric S. Raymond (author of The New Hacker’s Dictionary) advocates that members of the computer underground should be called crackers. Yet, those people see themselves as hackers and even try to include the views of Raymond in what they see as one wider hacker culture, a view harshly rejected by Raymond himself. Instead of a hacker/cracker dichotomy, they give more emphasis to a spectrum of different categories, such as white hatgrey hatblack hat and script kiddie. In contrast to Raymond, they usually reserve the term cracker. According to (Clifford R.D. 2006) a cracker or cracking is to “gain unauthorized access to a computer in order to commit another crime such as destroying information contained in that system”.[9] These subgroups may also be defined by the legal status of their activities.[10]

White hat
white hat hacker breaks security for non-malicious reasons, for instance testing their own security system. This classification also includes individuals who perform penetration tests andvulnerability assessments within a contractual agreement. Often, this type of ‘white hat’ hacker is called an ethical hacker. The International Council of Electronic Commerce Consultants, also known as the EC-Council has developed certifications, courseware, classes, and online training covering the diverse arena of Ethical Hacking.[10]
Black hat
A Black Hat Hacker is a hacker who “violates computer security for little reason beyond maliciousness or for personal gain”(Moore,2005). Black Hat Hackers are “the epitome of all that the public fears in a computer criminal”(Moore,2006). Black Hat Hackers break into secure networks to destroy data or make the network unusable for those who are authorized to use the network.

The way Black Hat Hackers choose the networks that they are going to break into is by a process that can be broken down into two parts. This is called the pre-hacking stage.

Part 1 Targeting Targeting is when the hacker determines what network to break into. The target may be of particular interest to the hacker, or the hacker may “Port Scan” a network to determine if it is vulnerable to attacks. A port is defined as “an opening through which the computer receives data via the network”(Moore,2005). Open ports 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 dive into a dumpster in hopes to find documents that users have thrown away, which will help them gain access to a network.

Grey hat
grey hat hacker is a combination of a Black Hat and a White Hat Hacker. A Grey Hat Hacker may surf the internet and hack into a computer system for the sole purpose of notifying the administrator that their system has been hacked, for example. Then they may offer to repair their system for a small fee.[4]
Elite hacker
social status among hackers, elite is used to describe the most skilled. Newly discovered exploits will circulate among these hackers. Elite groups such as Masters of Deception conferred a kind of credibility on their members.[11]:86,90,117 Elite (e.g. 31337) gives the term leet speak its name.
Script kiddie
script kiddie is a non-expert who breaks into computer systems by using pre-packaged automated tools written by others, usually with little understanding of the underlying concept—hence the term script (i.e. a prearranged plan or set of activities) kiddie (i.e. kid, child—an individual lacking knowledge and experience, immature).[12]
A neophyte, “n00b”, or “newbie” is someone who is new to hacking or phreaking and has almost no knowledge or experience of the workings of technology, and hacking.[4]
Blue hat
blue hat hacker is someone outside computer security consulting firms 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.[13][14][15]
A hacktivist is a hacker who utilizes technology to announce a social, ideological, religious, or political message. In general, most hacktivism involves website defacement or denial-of-service attacks. In more extreme cases, hacktivism is used as tool for cyberterrorism.


Main article: Computer insecurity
Computer security
Secure operating systems
Security architecture
Security by design
Secure coding
Computer insecurity
Vulnerability Social engineering
Exploits Trojans
Viruses and worms
Denial of service
Payloads Backdoors
v · d · e

A typical approach in an attack on Internet-connected system is:

  1. Network enumeration: Discovering information about the intended target.
  2. Vulnerability analysis: Identifying potential ways of attack.
  3. Exploitation: Attempting to compromise the system by employing the vulnerabilities found through the vulnerability analysis.[16]

In order to do so, there are several recurring tools of the trade and techniques used by computer criminals and security experts.

[edit]Security exploits

A security exploit is a prepared application that takes advantage of a known weakness. Common examples of security exploits are SQL injectionCross Site Scripting and Cross Site Request Forgery which abuse security holes that may result from substandard programming practice. Other exploits would be able to be used through FTPHTTPPHPSSHTelnet and some web-pages. These are very common in website/domain hacking.


Vulnerability scanner
vulnerability scanner is a tool used to quickly check computers on a network for known weaknesses. Hackers also commonly use port scanners. These check to see which ports on a specified computer are “open” or available to access the computer, and sometimes will detect what program or service is listening on that port, and its version number. (Note that firewalls defend computers from intruders by limiting access to ports/machines both inbound and outbound, but can still be circumvented.)
Password cracking
Password cracking is the process of recovering passwords from data that has been stored in or transmitted by a computer system. A common approach is to repeatedly try guesses for the password.
Packet sniffer
packet sniffer is an application that captures data packets, which can be used to capture passwords and other data in transit over the network.
Spoofing attack (Phishing)
spoofing attack involves one program, system, or website successfully masquerading as another by falsifying data and thereby being treated as a trusted system by a user or another program. The purpose of this is usually to fool programs, systems, or users into revealing confidential information, such as user names and passwords, to the attacker.
rootkit is designed to conceal the compromise of a computer’s security, and can represent any of a set of programs which work to subvert control of an operating system from its legitimate operators. Usually, a rootkit will obscure its installation and attempt to prevent its removal through a subversion of standard system security. Rootkits may include replacements for system binaries so that it becomes impossible for the legitimate user to detect the presence of the intruder on the system by looking at process tables.
Social engineering
Social engineering When a Hacker, typically a black hat, is in the second stage of the targeting process, he or she will typically use some social engineering tactics to get enough information to access the network. A common practice for hackers who use this technique, is to contact the system administrator and play the role of a user who cannot get access to his or her system. Hackers who use this technique have to be quite savvy and choose the words they use carefully, in order to trick the system administrator into giving them information. In some cases only an employed help desk user will answer the phone and they are generally easy to trick. Another typical hacker approach is for the hacker to act like a very angry supervisor and when the his/her authority is questioned they will threaten the help desk user with their job. Social Engineering is so effective because users are the most vulnerable part of an organization. All the security devices and programs in the world wont keep an organization safe if an employee gives away a password. Black Hat Hackers take advantage of this fact. Social Engineering can also be broken down into four sub-groups. These are intimidation, helpfulness, technical, and name-dropping.

Intimidation As stated above, with the angry supervisor, the hacker attacks the person who answers the phone with threats to their job. Many people at this point will accept that the hacker is a supervisor and give them the needed information.

Helpfulness Opposite to intimidation, helpfulness is taking advantage of a person natural instinct to help someone with a problem. The hacker will not get angry instead act very distressed and concerned. The help desk is the most vulnerable to this type of Social Engineering, because they generally have the authority to change or reset passwords which is exactly what the hacker needs.

Name-Dropping Simply put the hacker uses the names of advanced users as “key words”, and gets the person who answers the phone to believe that they are part of the company because of this. Some information, like web page ownership, can be obtained easily on the web. Other information such as president and vice president names might have to be obtained via dumpster diving.

Technical Using technology to get information is also a great way to get it. A hacker can send a fax or an email to a legitimate user in hopes to get a response containing vital information. Many times the hacker will act like he/she is involved with law enforcement and needs certain data for record keeping purposes or investigations.

Trojan horses
Trojan horse is a program which seems to be doing one thing, but is actually doing another. A trojan horse can be used to set up a back door in a computer system such that the intruder can gain access later. (The name refers to the horse from the Trojan War, with conceptually similar function of deceiving defenders into bringing an intruder inside.)
virus is a self-replicating program that spreads by inserting copies of itself into other executable code or documents. Therefore, a computer virus behaves in a way similar to a biological virus, which spreads by inserting itself into living cells.
While some are harmless or mere hoaxes most computer viruses are considered malicious.
Like a virus, a worm is also a self-replicating program. A worm differs from a virus in that it propagates through computer networks without user intervention. Unlike a virus, it does not need to attach itself to an existing program. Many people conflate the terms “virus” and “worm”, using them both to describe any self-propagating program.
Key loggers
key logger is a tool designed to record (‘log’) every keystroke on an affected machine for later retrieval. Its purpose is usually to allow the user of this tool to gain access to confidential information typed on the affected machine, such as a user’s password or other private data. Some key loggers uses virus-, trojan-, and rootkit-like methods to remain active and hidden. However, some key loggers are used in legitimate ways and sometimes to even enhance computer security. As an example, a business might have a key logger on a computer used at a point of sale and data collected by the key logger could be used for catching employee fraud.


This is why each organization needs to train their employees with what they should and should not do, security wise. “Training should be creative, varied, related to real life, and frequent.”(Tipton,2007) In addition “The attitude of the trainers should be to raise the awareness and behavior of the attendees to a higher level, not to explain the rules as if to criminals that they had “better behave or else.””(Tipton,2007)”Training for a user must include the proper use of the system and the reasons for the various controls and security parameters built into the system. Without divulging the details of the controls, explaining the reasons for the controls may help the users to accept and adhere to the security restrictions built into the system.”(Tipton,2007) When users are fully trained with how to keep their information and others information secure, they must also be taught to always follow procedure. If an employee is told not to give away a user name or password unless some other important information is provided, then they must not give away that information unless that are 100% sure the user is valid.

Other Useful Tips Other things you can do to prevent Black Hat Hackers from accessing your systems include: Job Rotation and Segregation of Duties. Job Rotation will keep users learning and adapting to different parts of the organization. Job Rotation will also keep users from “getting used to” their job. If a user sits around doing the same thing day after day they tend to slack off more, a business owner will get more “bang for their buck” and overall security using this technique. Segregation of Duties is also vital to network security. Do not give a single user more access to information or more responsibility then is absolutely necessary. A good example of this is having one user input data, and another user to process the data. Should either users information get out, it is much less of a security risk then if they had control over the entire process.


[edit]Notable intruders and criminal hackers

[edit]Notable security hackers

Main article: List of hackers

[edit]Hacking and the media

This section is in a list format that may be better presented using prose. You can help by converting this section to prose, if appropriate.Editing help is available. (August 2008)

[edit]Hacker magazines

Main category: Hacker magazines.

The most notable hacker-oriented magazine publications are PhrackHakin9 and 2600: The Hacker Quarterly. While the information contained in hacker magazines and ezines was often outdated, they improved the reputations of those who contributed by documenting their successes.[8]

[edit]Hackers in fiction

Hackers often show an interest in fictional cyberpunk and cyberculture literature and movies. Absorption of fictional pseudonyms, symbols, values, and metaphors from these fictional works is very common.[citation needed]

Books portraying hackers:

Films also portray hackers:

[edit]Non-fiction books

[edit]Fiction books

[edit]See also










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