An ethical hacker or pen tester generally conducts pen testing to break into corporate information systems and identify and exploit known and unknown vulnerabilities before an actual attacker or a malicious actor does. Pen testing involves simulated breaching of any number of applications or systems such as application protocol interfaces, front-end or back-end servers, security infrastructure, and unsensitised inputs to detect vulnerabilities and threats. The pen testing process usually includes five stages and helps the organisation to fine-tune their environment for fixing security loopholes.