A cracker (also known as a black hat hacker) is an individual with extensive computer knowledge whose purpose is to breach or bypass internet security or gain access to software without paying royalties. The general view is that, while hackers build things, crackers break things. Cracker is the name given to hackers who break into computers for criminal gain; whereas, hackers can also be internet security experts hired to find vulnerabilities in systems. These hackers are also known as white hat hackers. Crackers’ motivations can range from profit, a cause they believe in, general maliciousness or just because they like the challenge. They may steal credit card numbers, leave viruses, destroy files or collect personal information to sell.
Crackers can also refer to those who reverse engineer software and modify it for their own amusement. The most common way crackers gain access to networks or systems is through social engineering, whereby the cracker contacts employees at a company and tricks them into divulging passwords and other information that allows a cracker to gain access.