Hackers are skilled individuals in information technology who use their technical knowledge to achieve a goal or overcome a challenge within a computer system in non-standard ways. Although the term is popularly associated with security breaches—where hackers exploit vulnerabilities to gain illegal access to computer systems and data—it can also be applied to legal activities. For instance, law enforcement agencies sometimes use hacking techniques to gather evidence on criminals, and software companies, like Microsoft, hire ethical hackers to find and fix system vulnerabilities.

Definition of Hackers

The term “hacker” has two primary definitions. The first refers to individuals passionate about advanced information technology, often dedicated to programming subcultures. The second refers to those who breach computer security for malicious purposes. Over time, due to media coverage, the word “hacker” has become synonymous with cybercriminals. However, a subset of the hacking community began developing terms like “crackers,” “black-hat hackers,” “white-hat hackers,” and “gray-hat hackers” to distinguish between legal and illegal hacking activities, especially after the introduction of anti-hacking laws.

Types of Security Hackers

Within the hacker community, there are security hackers who are involved in bypassing computer security systems. They fall into several categories:

• White-hat hackers: These hackers work to keep data safe from other intruders by identifying and fixing system vulnerabilities. They are often employed by the system’s owner and are paid well for their legal services, performed with permission.
• Black-hat hackers: These hackers have malicious intent, often stealing data for personal gain. Their activities are illegal, and they exploit system vulnerabilities to benefit themselves financially, such as selling access to other black-hat hackers.
• Gray-hat hackers: These hackers may occasionally violate laws or ethical standards but do so out of curiosity or a desire for a challenge, not with malicious intent like black-hat hackers.

While white-hat hackers often work publicly using their real names, black-hat hackers tend to operate in secret, using aliases to hide their identity. Despite differences, both groups share a common knowledge of computer security, creating overlap in their skillsets.

Famous Hacking Cases

Several hacking incidents have garnered significant attention over the years:

• Citibank Hack (1995): Russian programmer Vladimir Levin managed to steal $10 million by hacking Citibank’s phone system and accessing customer credentials. Though eventually caught, he almost got away with the money, with only $400,000 still unaccounted for.
• Melissa Virus (1999): Created by David Smith, this virus spread via a Word document attached to emails. It infected 20% of the world’s computers, causing major business disruptions, though no sensitive information was stolen. Smith received a 20-month prison sentence.
• MafiaBoy Attacks (2000): A 15-year-old hacker, Michael Calce (known as MafiaBoy), launched a series of Distributed Denial-of-Service (DDoS) attacks, bringing down major websites like CNN, Yahoo, and Amazon. His motivation was to impress the hacking community, and he eventually served eight months in a juvenile detention center.
• U.S. Military Hack (2001): Scottish hacker Gary McKinnon accessed 97 U.S. military systems in search of UFO evidence. He caused significant damage, with recovery efforts costing the U.S. over $800,000. Though the U.S. sought his extradition, McKinnon avoided trial and prosecution.
• Heartland Payment Systems Breach (2008): Hackers infiltrated one of the world’s largest credit card processors, Heartland Payment Systems, and accessed 130 million customer accounts. Albert Gonzalez was later arrested and sentenced to 20 years for his role in the theft.

These cases illustrate the range of hacker motivations, from financial gain to personal curiosity, and demonstrate the significant impact hacking can have on businesses, governments, and individuals worldwide.