Published on Sep 21, 2019
During the devolpment of the Internet, computer security has become a major concern for businesses and governments. They want to be able to take advantage of the Internet for electronic commerce, advertising, information distribution and access, and other pursuits, but they are worried about the possibility of being "hacked."
At the same time, the potential customers of these services are worried about maintaining control of personal information that varies from credit card numbers to social security numbers and home addresses.In their search for a way to approach the problem, organizations came to realize that one of the best ways to evaluate the intruder threat to their interests would be to have independent computer security professionals attempt to break into their computer systems.
This scheme is similar to having independent auditors come into an organization to verify its bookkeeping records. In the case of computer security, these "tiger teams" or "ethical hackers" would employ the same tools and techniques as the intruders, but they would neither damage the target systems nor steal information. Instead, they would evaluate the target systems' security and report back to the owners with the vulnerabilities they found and instructions for how to remedy them.
This method of evaluating the security of a system has been in use from the early days of computers. In one early ethical hack, the United States Air Force conducted a "security evaluation" of the Multics operating systems for "potential use as a two-level (secret/top secret) system." Their evaluation found that while Multics was "significantly better than other conventional systems," it also had " . vulnerabilities in hardware security, software security, and procedural security" that could be uncovered with "a relatively low level of effort."
The authors performed their tests under a guideline of realism, so that their results would accurately represent the kinds of access that an intruder could potentially achieve. They performed tests that were simple information-gathering exercises, as well as other tests that were outright attacks upon the system that might damage its integrity. Clearly, their audience wanted to know both results. There are several other now unclassified reports that describe ethical hacking activities within the U.S. military.
With the growth of computer networking, and of the Internet in particular, computer and network vulnerability studies began to appear outside of the military establishment. Most notable of these was the work by Farmer and Venema, which was originally posted to Usenet in December of 1993. They discussed publicly, perhaps for the first time, this idea of using the techniques of the hacker to assess the security of a system. With the goal of raising the overall level of security on the Internet and intranets, they proceeded to describe how they were able to gather enough information about their targets to have been able to compromise security if they had chosen to do so. They provided several specific examples of how this information could be gathered and exploited to gain control of the target, and how such an attack could be prevented
What do ethical hackers do?
An ethical hacker's evaluation of a system's security seeks answers to three basic questions:
What can an intruder see on the target systems?
What can an intruder do with that information?
Does anyone at the target notice the intruder's attempts or successes?
Who are ethical hackers?
Successful ethical hackers possess a variety of skills. First and foremost, they must be completely trustworthy. While testing the security of a client's systems, the ethical hacker may discover information about the client that should remain secret. In many cases, this information, if publicized, could lead to real intruders breaking into the systems, possibly leading to financial losses. During an evaluation, the ethical hacker often holds the “keys to the company,” and therefore must be trusted to exercise tight control over any information about a target that could be misused.
The sensitivity of the information gathered during an evaluation requires that strong measures be taken to ensure the security of the systems being employed by the ethical hackers themselves: limited-access labs with physical security protection and full ceiling-to-floor walls, multiple secure Internet connections, a safe to hold paper documentation from clients, strong cryptography to protect electronic results, and isolated networks for testing.
Ethical hackers typically have very strong programming and computer networking skills and have been in the computer and networking business for several years. They are also adept at installing and maintaining systems that use the more popular operating systems (e.g., UNIX or Windows NT) used on target systems. These base skills are augmented with detailed knowledge of the hardware and software provided by the more popular computer and networking hardware vendors. It should be noted that an additional specialization in security is not always necessary, as strong skills in the other areas imply a very good understanding of how the security on various systems is maintained. These systems management skills are necessary for the actual vulnerability testing, but are equally important when preparing the report for the client after the test.
Finally, good candidates for ethical hacking have more drive and patience than most people. Unlike the way someone breaks into a computer in the movies, the work that ethical hackers do demands a lot of time and persistence. This is a critical trait, since criminal hackers are known to be extremely patient and willing to monitor systems for days or weeks while waiting for an opportunity.
A typical evaluation may require several days of tedious work that is difficult to automate. Some portions of the evaluations must be done outside of normal working hours to avoid interfering with production at “live” targets or to simulate the timing of a real attack. When they encounter a system with which they are unfamiliar, ethical hackers will spend the time to learn about the system and try to find its weaknesses. Finally, keeping up with the ever-changing world of computer and network security requires continuous education and review.
One might observe that the skills we have described could just as easily belong to a criminal hacker as to an ethical hacker. Just as in sports or warfare, knowledge of the skills and techniques of your opponent is vital to your success. In the computer security realm, the ethical hacker's task is the harder one. With traditional crime anyone can become a shoplifter, graffiti artist, or a mugger. Their potential targets are usually easy to identify and tend to be localized. The local law enforcement agents must know how the criminals ply their trade and how to stop them. On the Internet anyone can download criminal hacker tools and use them to attempt to break into computers anywhere in the world. Ethical hackers have to know the techniques of the criminal hackers, how their activities might be detected, and how to stop them
While the first and second of these are clearly important, the third is even more important: If the owners or operators of the target systems do not notice when someone is trying to break in, the intruders can, and will, spend weeks or months trying and will usually eventually succeed.
When the client requests an evaluation, there is quite a bit of discussion and paperwork that must be done up front