Security hacker

A security hacker is someone who seeks to breach defenses and exploit weaknesses in a computer system or network. Hackers may be motivated by a multitude of reasons, such as profit, protest, information gathering,^[1] challenge, recreation,^[2]or to evaluate system weaknesses to assist in formulating defenses against potential hackers. The subculture that has evolved around hackers is often referred to as the computer underground.^[3]

There is a longstanding controversy about the term's true meaning. In this controversy, the term hacker is reclaimed by computer programmers who argue that it refers simply to someone with an advanced understanding of computers and computer networks,^[4] and that cracker is the more appropriate term for those who break into computers, whether computer criminal (black hats) or computer security expert (white hats).^[5][6] A 2014 article concluded that "... the black-hat meaning still prevails among the general public".^[7][tone]

In computer security, a hacker is someone who focuses on security mechanisms of computer and network systems. While including those who endeavor to strengthen such mechanisms, it is more often used by the mass media and popular culture to refer to those who seek access despite these security measures. That is, the media portrays the 'hacker' as a villain. Nevertheless, parts of the subculture see their aim in correcting security problems and use the word in a positive sense. White hat is the name given to ethical computer hackers, who utilize hacking in a helpful way. White hats are becoming a necessary part of the information security field.^[8]They operate under a code, which acknowledges that breaking into other people's computers is bad, but that discovering and exploiting security mechanisms and breaking into computers is still an interesting activity that can be done ethically and legally. Accordingly, the term bears strong connotations that are favorable or pejorative, depending on the context.

The subculture around such hackers is termed network hacker subculture, hacker scene, or computer underground. It initially developed in the context of phreaking during the 1960s and the microcomputer BBS scene of the 1980s. It is implicated with 2600: The Hacker Quarterly and the alt.2600 newsgroup.

In 1980, an article in the August issue of Psychology Today(with commentary by Philip Zimbardo) used the term "hacker" in its title: "The Hacker Papers". It was an excerpt from a Stanford Bulletin Board discussion on the addictive nature of computer use. In the 1982 film Tron, Kevin Flynn (Jeff Bridges) describes his intentions to break into ENCOM's computer system, saying "I've been doing a little hacking here". CLU is the software he uses for this. By 1983, hacking in the sense of breaking computer security had already been in use as computer jargon,^[9] but there was no public awareness about such activities.^[10] However, the release of the film WarGamesthat year, featuring a computer intrusion into NORAD, raised the public belief that computer security hackers (especially teenagers) could be a threat to national security. This concern became real when, in the same year, a gang of teenage hackers in Milwaukee, Wisconsin, known as The 414s, broke into computer systems throughout the United States and Canada, including those of Los Alamos National Laboratory, Sloan-Kettering Cancer Center and Security Pacific Bank.^[11] The case quickly grew media attention,^[11][12] and 17-year-old Neal Patrick emerged as the spokesman for the gang, including a cover story in Newsweek entitled "Beware: Hackers at play", with Patrick's photograph on the cover.^[13] The Newsweekarticle appears to be the first use of the word hacker by the mainstream media in the pejorative sense.

Pressured by media coverage, congressman Dan Glickmancalled for an investigation and began work on new laws against computer hacking.^[14][15] Neal Patrick testified before the U.S. House of Representatives on September 26, 1983, about the dangers of computer hacking, and six bills concerning computer crime were introduced in the House that year.^[15] As a result of these laws against computer criminality, white hat, grey hat and black hat hackers try to distinguish themselves from each other, depending on the legality of their activities. These moral conflicts are expressed in The Mentor's "The Hacker Manifesto", published 1986 in Phrack.

Use of the term hacker meaning computer criminal was also advanced by the title "Stalking the Wily Hacker", an article by Clifford Stoll in the May 1988 issue of the Communications of the ACM. Later that year, the release by Robert Tappan Morris, Jr. of the so-called Morris worm provoked the popular media to spread this usage. The popularity of Stoll's book The Cuckoo's Egg, published one year later, further entrenched the term in the public's consciousness.

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.^[28]

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

Security exploits

Main article: Exploit (computer security)

A security exploit is a prepared application that takes advantage of a known weakness.^[29] Common examples of security exploits are SQL injection, cross-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 File Transfer Protocol (FTP), Hypertext Transfer Protocol (HTTP), PHP, SSH, Telnet and some Web pages. These are very common in Web site and Web domain hacking.

Techniques

This section does not cite any sources.

Vulnerability scanner

A 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. (Firewalls defend computers from intruders by limiting access to ports and machines, but they can still be circumvented.)

Finding vulnerabilities

Hackers may also attempt to find vulnerabilities manually. A common approach is to search for possible vulnerabilities in the code of the computer system then test them, sometimes reverse engineering the software if the code is not provided. Experienced hackers can easily find patterns in code to find common vulnerabilities.

Brute-force attack

Password guessing. This method is very fast when used to check all short passwords, but for longer passwords other methods such as the dictionary attack are used, because of the time a brute-force search takes.^[30]

Password cracking

Password cracking is the process of recovering passwords from data that has been stored in or transmitted by a computer system. Common approaches include repeatedly trying guesses for the password, trying the most common passwords by hand, and repeatedly trying passwords from a "dictionary", or a text file with many passwords.

Packet analyzer

A packet analyzer ("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)

A spoofing attack involves one program, system or website that successfully masquerades as another by falsifying data and is thereby treated as a trusted system by a user or another program — usually to fool programs, systems or users into revealing confidential information, such as user names and passwords.

Rootkit

A rootkit is a program that uses low-level, hard-to-detect methods to subvert control of an operating system from its legitimate operators. Rootkits usually obscure their installation and attempt to prevent their removal through a subversion of standard system security. They may include replacements for system binaries, making it virtually impossible for them to be detected by checking process tables.

Social engineering

In the second stage of the targeting process, hackers often use Social engineering tactics to get enough information to access the network. They may contact the system administrator and pose as a user who cannot get access to his or her system. This technique is portrayed in the 1995 film Hackers, when protagonist Dade "Zero Cool" Murphy calls a somewhat clueless employee in charge of security at a television network. Posing as an accountant working for the same company, Dade tricks the employee into giving him the phone number of a modem so he can gain access to the company's computer system.

Hackers who use this technique must have cool personalities, and be familiar with their target's security practices, in order to trick the system administrator into giving them information. In some cases, a help-desk employee with limited security experience will answer the phone and be relatively easy to trick. Another approach is for the hacker to pose as an angry supervisor, and when his/her authority is questioned, threaten to fire the help-desk worker. Social engineering is very effective, because users are the most vulnerable part of an organization. No security devices or programs can keep an organization safe if an employee reveals a password to an unauthorized person.

Social engineering can be broken down into four sub-groups:

• Intimidation As in the "angry supervisor" technique above, the hacker convinces the person who answers the phone that their job is in danger unless they help them. At this point, many people accept that the hacker is a supervisor and give them the information they seek.
• Helpfulness The opposite of intimidation, helpfulness exploits many people's natural instinct to help others solve problems. Rather than acting angry, the hacker acts distressed and concerned. The help desk is the most vulnerable to this type of social engineering, as (a.) its general purpose is to help people; and (b.) it usually has the authority to change or reset passwords, which is exactly what the hacker wants.^[31]
• Name-dropping The hacker uses names of authorized users to convince the person who answers the phone that the hacker is a legitimate user him or herself. Some of these names, such as those of webpage owners or company officers, can easily be obtained online. Hackers have also been known to obtain names by examining discarded documents ("dumpster diving").
• Technical Using technology is also a way to get information. A hacker can send a fax or email to a legitimate user, seeking a response that contains vital information. The hacker may claim that he or she is involved in law enforcement and needs certain data for an investigation, or for record-keeping purposes.

Trojan horses

A Trojan horse is a program that seems to be doing one thing but is actually doing another. It can be used to set up a back door in a computer system, enabling the intruder to gain access later. (The name refers to the horse from the Trojan War, with the conceptually similar function of deceiving defenders into bringing an intruder into a protected area.)

Computer virus

A virus is a self-replicating program that spreads by inserting copies of itself into other executable code or documents. By doing this, it behaves similarly to a biological virus, which spreads by inserting itself into living cells. While some viruses are harmless or mere hoaxes, most are considered malicious.

Computer worm

Like a virus, a worm is also a self-replicating program. It differs from a virus in that (a.) it propagates through computer networks without user intervention; and (b.) does not need to attach itself to an existing program. Nonetheless, many people use the terms "virus" and "worm" interchangeably to describe any self-propagating program.

Keystroke logging

A keylogger is a tool designed to record ("log") every keystroke on an affected machine for later retrieval, usually to allow the user of this tool to gain access to confidential information typed on the affected machine. Some keyloggers use virus-, trojan-, and rootkit-like methods to conceal themselves. However, some of them are used for legitimate purposes, even to enhance computer security. For example, a business may maintain a keylogger on a computer used at a point of sale to detect evidence of employee fraud.

Attack patterns

Attack patterns are defined as series of repeatable steps that can be applied to simulate an attack against the security of a system. They can be used for testing purposes or locating potential vulnerabilities. They also provide, either physically or in reference, a common solution pattern for preventing a given attack.

Tools and Procedures