In television and film westerns, the bad guys always wore shabby clothes, looked mean and sinister, and lived in gangs somewhere out of town. By contrast, the sheriff dressed well, stood proud and tall, was known and respected by everyone in town, and struck fear in the hearts of most criminals.
To be sure, some computer criminals are mean and sinister types. But many more wear business suits, have university degrees, and appear to be pillars of their communities. Some are high school or university students. Others are middle-aged business executives. Some are mentally deranged, overtly hostile, or extremely committed to a cause, and they attack computers as a symbol. Others are ordinary people tempted by personal profit, revenge, challenge, advancement, or job security. No single profile captures the characteristics of a "typical" computer criminal, and many who fit the profile are not criminals at all.
Whatever their characteristics and motivations, computer criminals have access to enormous amounts of hardware, software, and data; they have the potential to cripple much of effective business and government throughout the world. In a sense, then, the purpose of computer security is to prevent these criminals from doing damage.
For the purposes of studying computer security, we say computer crime is any crime involving a computer or aided by the use of one. Although this definition is admittedly broad, it allows us to consider ways to protect ourselves, our businesses, and our communities against those who use computers maliciously.
The U.S. Federal Bureau of Investigation regularly reports uniform crime statistics. The data do not separate computer crime from crime of other sorts. Moreover, many companies do not report computer crime at all, perhaps because they fear damage to their reputation, they are ashamed to have allowed their systems to be compromised, or they have agreed not to prosecute if the criminal will "go away." These conditions make it difficult for us to estimate the economic losses we suffer as a result of computer crime; our dollar estimates are really only vague suspicions. Still, the estimates, ranging from $300 million to $ 500 billion per year, tell us that it is important for us to pay attention to computer crime and to try to prevent it or at least to moderate its effects.
One approach to prevention or moderation is to understand who commits these crimes and why. Many studies have attempted to determine the characteristics of computer criminals. By studying those who have already used computers to commit crimes, we may be able in the future to spot likely criminals and prevent the crimes from occurring. In this section, we examine some of these characteristics.
Amateurs have committed most of the computer crimes reported to date. Most embezzlers are not career criminals but rather are normal people who observe a weakness in a security system that allows them to access cash or other valuables. In the same sense, most computer criminals are ordinary computer professionals or users who, while doing their jobs, discover they have access to something valuable.
When no one objects, the amateur may start using the computer at work to write letters, maintain soccer league team standings, or do accounting. This apparently innocent time-stealing may expand until the employee is pursuing a business in accounting, stock portfolio management, or desktop publishing on the side, using the employer's computing facilities. Alternatively, amateurs may become disgruntled over some negative work situation (such as a reprimand or denial of promotion) and vow to "get even" with management by wreaking havoc on a computing installation.
Crackers or Malicious Hackers
System crackers, often high school or university students, attempt to access computing facilities for which they have not been authorized. Cracking a computer's defenses is seen as the ultimate victimless crime. The perception is that nobody is hurt or even endangered by a little stolen machine time. Crackers enjoy the simple challenge of trying to log in, just to see whether it can be done. Most crackers can do their harm without confronting anybody, not even making a sound. In the absence of explicit warnings not to trespass in a system, crackers infer that access is permitted. An underground network of hackers helps pass along secrets of success; as with a jigsaw puzzle, a few isolated pieces joined together may produce a large effect. Others attack for curiosity, personal gain, or self-satisfaction. And still others enjoy causing chaos, loss, or harm. There is no common profile or motivation for these attackers.
By contrast, the career computer criminal understands the targets of computer crime. Criminals seldom change fields from arson, murder, or auto theft to computing; more often, criminals begin as computer professionals who engage in computer crime, finding the prospects and payoff good. There is some evidence that organized crime and international groups are engaging in computer crime. Recently, electronic spies and information brokers have begun to recognize that trading in companies' or individuals' secrets can be lucrative.
Recent attacks have shown that organized crime and professional criminals have discovered just how lucrative computer crime can be. Mike Danseglio, a security project manager with Microsoft, said, "In 2006, the attackers want to pay the rent. They don't want to write a worm that destroys your hardware. They want to assimilate your computers and use them to make money" [NAR06a]. Mikko Hyppönen, Chief Research Officer with the Finnish security company f-Secure, agrees that today's attacks often come from Russia, Asia, and Brazil and the motive is now profit, not fame [BRA06]. Ken Dunham, Director of the Rapid Response Team for Verisign says he is "convinced that groups of well-organized mobsters have taken control of a global billion-dollar crime network powered by skillful hackers" [NAR06b].
Snow [SNO05] observes that a hacker wants a score, bragging rights. Organized crime wants a resource; they want to stay and extract profit from the system over time. These different objectives lead to different approaches: The hacker can use a quick-and-dirty attack, whereas the professional attacker wants a neat, robust, and undetected method.
As mentioned earlier, some companies are reticent to prosecute computer criminals. In fact, after having discovered a computer crime, the companies are often thankful if the criminal quietly resigns. In other cases, the company is (understandably) more concerned about protecting its assets and so it closes down an attacked system rather than gathering evidence that could lead to identification and conviction of the criminal. The criminal is then free to continue the same illegal pattern with another company.
The link between computers and terrorism is quite evident. We see terrorists using computers in three ways:
targets of attack: denial-of-service attacks and web site defacements are popular for any political organization because they attract attention to the cause and bring undesired negative attention to the target of the attack.
propaganda vehicles: web sites, web logs, and e-mail lists are effective, fast, and inexpensive ways to get a message to many people.
methods of attack: to launch offensive attacks requires use of computers.
We cannot accurately measure the amount of computer-based terrorism because our definitions and measurement tools are rather weak. Still, there is evidence that all three of these activities are increasing.