Penetration Testing Interview Questions And Sample Answers

Updated 9 October 2022

A penetration test, also known as a pen test, checks the security system of an IT infrastructure. A pen test helps to understand and mitigate the vulnerabilities to a company's systems. As a penetration tester, you can conduct simulated cyberattacks to check the company's computer systems and identify potential vulnerabilities in the system. In this article, we review some of the common penetration testing interview questions, different types of penetration tests and how penetration testing helps an organisation avert cyber-attacks.

Penetration Testing Interview Questions

Here are some penetration testing interview questions along with sample answers:

1. How would you describe information security? Is it the same as cybersecurity?

This question is common for a pen tester's interview, as knowing the difference between information security and cybersecurity requires a basic understanding of the subject. Interviewers want to know if candidates know the difference between the two terms from a practical perspective. As pen testers handle IT security, in your answer, consider explaining information security in detail, followed by explaining how it differs from cybersecurity.

Example: 'Information security is the practice of safeguarding sensitive company data by checking information-related risks. An insecure IT network can pose a major threat to the company. Information security prevents unauthorised access to data and puts measures in place to reduce the adverse impacts of such cyber attacks. It also aims to protect data confidentiality without hampering organisational productivity.

People often use information security and cybersecurity interchangeably. While cybersecurity is concerned only with protecting information in cyberspace, information security deals with protecting the data even beyond cyberspace. Information security includes overall system security while cyber security deals only with online threats.'

2. Why is penetration testing important?

Interviewers want you to know whether you have an idea about the role. Provide them with a concise overview of the importance of pen testing for a company. Include the security threats a pen tester typically deals with.

Example: 'Malicious entities can attack company systems which lead to a data breach. Penetration testing is important as it helps employees to learn how to deal with any kind of cyber threat to the organisation's systems. These tests are a way to ensure that the company's security policies are effective.

Pen tests do not simply check the company's preparedness against an attack. They also expel these attacks from the system and provide solutions to defend against such attacks in the future. Reports generated by a penetration test can help developers understand how external entities attacked the system and draft a better plan to secure these systems in the future.'

3. Mention some tools that help to conduct a penetration test

This question tests your technical knowledge as a pen tester. Avoid giving a one-line answer. Start with a brief explanation of what pen testing tools and what their functions are. Provide some examples of pen testing tools at the end to complete the answer.

Example: 'Penetration testing tools help to detect security threats to the network by using software applications. A penetration tester's toolkit may include a variety of tools, depending on the kind of engagement needed for the test. Pen testing tools can range from port and vulnerability scanners to network sniffer and password cracker. Some of the common penetration tools are NetSparker, AirCrack and Wireshark.'

4. How long does it take to perform a penetration test?

Interviewers want to hear about your prior experience in penetration testing. Refer to your previous roles to answer this. You can also explain some of the important factors that impact the duration of a penetration test.

Example: 'From my previous experience I have noticed penetration test can take anywhere between one and three weeks. There are several factors that determine how long a penetration test might take. This includes the type of test, software being used for the test, the number of systems being tested and the level of security in the systems.'

5. Talk about the different stages of penetration testing

Interviewers want to know whether you are aware of every stage in penetration testing. Talking about every stage helps them understand how you have dealt with the process previously. You can use your knowledge and your prior experience to answer this question.

Example: 'There are five stages in penetration testing: planning, scanning, gaining access, maintaining access and analysis. In the first stage, testers define the goals and identify the scope of the pen test. During this stage, testers also gather information about potential targets and how vulnerable company systems are against such threats through search engine queries, tailgating and social engineering. The next stage is to understand how the target might respond to these threats through static and dynamic analysis. In the third stage, the tester tests the target application's exploits through standard tactics like web application or network attacks.

The fourth stage is where testers list the methods used to gain access to sensitive data. The penetration tester can also require determining the value of the compromised systems and any value associated with the sensitive data captured. Once the tester files their recommendations, it is important that they clean up the environment, including removing any rootkits or temporary files from potentially threatening systems. The final stage is to compile your findings into a report that offers the organisation insights into improving security.'

6. What do you think are the necessary skills to be a pen tester?

Through this question, the hiring manager tries to understand what you have learned from your previous experience. You may speak about your prior position as a pen tester and also add a few other skills that you think might be helpful. This helps interviewers gauge your skill levels and ability to guide other team members.

Example: 'The duties of a penetration tester depend on the company they work with. From my previous role as a pen tester, I have realised background knowledge about the kinds of vulnerabilities that may threaten company systems is one of the most important skills required to be a pen tester. It is also important that testers understand web technologies.

I also feel certain other skills may be useful to build a career in pen testing. This includes knowledge of how to conduct simulated cyberattacks, experimenting with different kinds of potential attacks, developing testing techniques that improve efficiency and familiarity with security and compliance issues. It might also be crucial for testers to know how to ideate methodologies for penetration testing.'

7. Do you have any certifications in pen testing? Or are you aware of any?

As pen testing is an ethical hacking tactic, the interviewer wants to know whether you have the necessary certification to carry it out. If not, you may list a few certifications that you are aware of and tell them that you want to enlist in any of them in the future. This ensures the interview panel that you are going to take your job seriously.

Example: I am a certified expert penetration tester or CEP tester. The CEPT tested my technical understanding and also analysed my problem-solving ability skills as a pen tester. I took a 50-question assessment, followed by a hands-on practicum to be certified as a CEPT.

There are also several other certifications available for aspiring penetration testers. The certified ethical hacker or CEH certification is a world-renowned accreditation for ethical hackers. The EC Security Council also offers a certification on penetration testing. Candidates take a 12-hour test to demonstrate their skills in threat detection, network scans and vulnerability analysis.

8. Do you know what is IDS? How is it different from IPS?

IDS and IPS help companies to better identify security attacks. They also improve security response. Interviewers want to know whether pen testers are aware of how an IDS and IPS work and how effective they can be against malicious threats.

Example: 'Company systems are always under threat of new exploits and attack techniques. An IDS, or intrusion detection system, is a network security application that helps companies detect and respond to security threats. The IDS triggers an alert every time the system detects a suspicious threat or activity. IT personnel can examine the threats closely and use the information to implement more effective controls. An IDS can protect against not just hackers but also other forms of malware and internet worms. Simply put, IDS protects against all kinds of security threats.

An IPS, or intrusion prevention system, is similar to an intrusion detection system, as both are used to monitor and report suspicious activities. The only difference is you can configure an IPS to eliminate threats. Unlike an IDS, IPS takes action itself and does not require an administrator's involvement to obstruct threats.'

Please note that none of the companies, institutions or organisations mentioned in this article are associated with Indeed.

Penetration Testing Interview Questions And Sample Answers