Explanation:
Penetration testing is the most intrusive type of testing because you are actively trying to circumvent the system’s security controls to gain access to the system. Penetration testing (also called pen testing) is the practice of testing a computer system, network or Web application to find vulnerabilities that an attacker could exploit. Pen tests can be automated with software applications or they can be performed manually. Either way, the process includes gathering information about the target before the test (reconnaissance), identifying possible entry points, attempting to break in (either virtually or for real) and reporting back the findings. The main objective of penetration testing is to determine security weaknesses. A pen test can also be used to test an organization’s security policy compliance, its employees’ security awareness and the organization’s ability to identify and respond to security incidents. Penetration tests are sometimes called white hat attacks because in a pen test, the good guys are attempting to break in.

Pen test strategies include:

Targeted testing Targeted testing is performed by the organization’s IT team and the penetration testing team working together. It’s sometimes referred to as a “lights-turned-on” approach because everyone can see the test being carried out.

External testing This type of pen test targets a company’s externally visible servers or devices including domain name servers (DNS), e-mail servers, Web servers or firewalls. The objective is to find out if an outside attacker can get in and how far they can get in once they’ve gained access.

Internal testing This test mimics an inside attack behind the firewall by an authorized user with standard access privileges. This kind of test is useful for estimating how much damage a disgruntled employee could cause.

Blind testing A blind test strategy simulates the actions and procedures of a real attacker by severely limiting the information given to the person or team that’s performing the test beforehand. Typically, they may only be given the name of the company. Because this type of test can require a considerable amount of time for reconnaissance, it can be expensive.

Double blind testing Double blind testing takes the blind test and carries it a step further. In this type of pen test, only one or two people within the organization might be aware a test is being conducted. Double-blind tests can be useful for testing an organization’s security monitoring and incident identification as well as its response procedures.