An ethical hacker (also known as a white-hat hacker) is the ultimate security professional. Ethical hackers know how to find and exploit vulnerabilities and weaknesses in various systems, just like a malicious hacker (or a black hat hacker). In fact, they both use the same skills; however, an ethical hacker uses those skills in a legitimate, lawful manner to try to find vulnerabilities and fix them before the bad guys can get there and try to break in.