Ethical Hacking Interview Questions and Answers 2021

Ethical hacking is a broad skill with numerous concepts to master. This is why preparing ethical hacking interview questions can be a bit challenging for many. 

To help you with your preparation, we have assorted the following list of our top ethical hacking interview questions and answers. It would help you get an idea of what you can expect from the interview. 

Top Ethical Hacking Interview Questions and Answers

1. What Do you Mean by Mac Address and IP Address?

Ans: The MAC (Machine Access Control) address is a unique serial number assigned to a network interface of every device. It’s similar to a physical mailbox where only the postal carrier (network router) can distinguish it. You can change the Mac address by getting a new network card. 

On the other hand, the IP address is the specific ID of a device such that we can locate the device on a network. We can say it’s like the postal address where anyone can send you a letter if they know your postal address. 

2. What Do you Mean by Ethical Hacking? What is an Ethical Hacker? 

Ans: Ethical hacking is when you hack into a system or device with the permission of its owner to find weak areas in its security or operation.

An ethical hacker is a computer security expert who specializes in multiple testing methodologies including penetration testing to check the security of an organization’s information systems. 

3. What is Footprinting? Do you Know any Footprinting Techniques?

Ans: Footprinting is the accumulation and uncovering of a target network’s information before gaining access to the same. Your focus in footprinting is to gain as much data as possible about your target network so you can plan your strategy and preferred testing methods.

There are the following types of footprinting:

Open Source Footprinting

Here, you will look for the contact information of the administrators so you can use it to guess passwords in social engineering. 

Network Enumeration

Here, you will try to find the domain names and the network blocks of the target.


Here you first find out the network and spy the active IP addresses to identify the Internet Control Message Protocol. 

Stack Fingerprinting

In stack fingerprinting, you map the hosts and port by scanning the network. After you have completed the scanning, you can conduct the final footprinting. 

Note: This is among the most important ethical hacking interview questions and answers, so you should prepare its answer with a little extra effort. 

4. Can you list out Some Ethical Hacking Tools? 

Ans: Following are some of the most popular ethical hacking tools available:

  • WireShark
  • Metasploit
  • Maltego
  • John the Ripper
  • NMAP

5. What is a DoS (Denial of Service) Attack?

Ans: A Denial of Service attack, also known as a DoS attack, focuses on shutting down a network and making it inaccessible to its users. It achieves this goal by flooding the target with traffic or sending it information that causes the target to crash.

6. What Do you Mean by a Brute Force Hack?

Ans: Brute force hack is a method to hack passwords and gain access to a system and its network resources. Here, you submit numerous passphrases and passwords hoping that you will eventually guess the correct combination.
You must systematically check all the possible passphrases and passwords to find the correct combination. Brute force hacking takes a lot of time and requires you to use JavaScript. The most suitable tool to perform a brute force attack is Hydra.

7. What is SQL Injection? 

Ans: SQL injection is a code injection technique we use to attack data-driven applications. Here, we insert malicious SQL statements into an entry field for execution which manipulates the backend database.
It allows us to access information which we aren’t allowed to access such as private customer data, sensitive information about the company or user lists.

8. What are the Most Prominent Types of DoS Attacks? 

Ans: Following are the most prominent types of DoS attacks: 

Here, you cause permanent damage to the system hardware by sending fake updates to the hardware. The only way to overcome this issue is to re-install new hardware.
Application Layer Attacks
In an application layer attack, you exploit the programming errors in an application to cause a DoS attack. Here, you send multiple application requests to the target and exhaust its resources so it becomes unable to service its valid clients.
TCP-State Exhaustion Attack
Here you set up and tear down the TCP connections and overwhelm the stable tables, which results in a DoS attack.
Fragmentation Attacks
In a fragmentation attack, you fight the reassembling ability of your target. You send multiple fragmented packets to the target and make it difficult for it to reassemble them, which denies access to the target’s clients.
Syn Flooding
In Syn flooding, you comprise multiple zombies and flood the target with multiple SYN packets. When you overwhelm the target with SYN requests, either its performance reduces drastically or it shuts down.
Volumetric Attacks
Here, you consume the entire bandwidth of a network so the authorized clients of your target wouldn’t get the resources. You do so by flooding the network devices such as the switches or hubs with multiple ICMP echo request (or reply) packets to consume the entire bandwidth. This way no other client can connect with the target. 

9. Do you Know the Types of Computer-Based Social Engineering Attacks? If so, What are They? 

Ans: Yes, I know the different types of computer-based social engineering attacks. The most prominent kinds of computer-based social engineering attacks are:

  • Phishing
  • Online scams
  • Baiting

10. What Do you Mean by ARP Spoofing or ARP Poisoning?

Ans: Address resolution protocol poisoning, also known as ARP poisoning or ARP spoofing, is when you send fraudulent ARP messages over a LAN (local area network) to link your MAC address with the IP address of a legitimate server or computer on the network.
Once your MAC address is linked, you can receive all the messages directed to the legitimate MAC address, allowing you to intercept, modify, and block communications to the legitimate MAC address.

11.What Do you mean by Phishing?

Ans: Phishing is a form of online scam where an attacker tries to obtain sensitive information such as passwords, passphrases, usernames, and other data by impersonating a legitimate or trustworthy organization. Phishing attacks occur through many digital media such as email, social media, text messages, and even phone calls.

12. How Would you Avoid ARP Poisoning? 

Ans: I can use multiple methods to prevent and avoid ARP poisoning. Here are the methods I would use to avoid ARP poisoning:

Use Cryptographic Network Protocols

You can use secure communication protocols such as HTTP, SSH, and TLS to prevent ARP spoofing attacks as they encrypt the data before transmission and authenticate it when it is received.

Conduct Packet Filtering
You can use packet filtering and inspection to catch poisoned packets before they reach their goal. It would allow you to avoid many ARP poisoning attacks.

Avoid Trust Relationships
Some systems use IP trust relations to automatically connect to particular devices to share data. However, you should completely avoid this feature and use proper verification systems as it makes it quite easy for a hacker to perform ARP spoofing when you have IP trust relationships.

Check Malware Monitoring Settings
The malware and antivirus tools you use may have features to protect you from ARP poisoning. You should check your malware monitoring settings and enable ARP spoofing prevention options to safeguard your network.

Use static ARP
You can create a static ARP entry in the server to reduce the risk of ARP spoofing. It would create a permanent entry in the ARP cache and add a layer of protection.

13. What is Network Sniffing?

Ans: A network sniffer monitors network traffic for data (such as where the traffic comes from, which protocols are used, etc.) It helps you view and capture packed data on the network and locate network problems. We use network sniffers in proper network management and in ethical hacking to steal information.

14. What is Mac Flooding? 

Ans: A media access control attack, also known as MAC flooding, is a method for compromising the security of network switches. In MAC flooding, you flood the network with fake MAC addresses to steal sensitive data that was being transferred into the network. Notice that you don’t attack any host machines in the network instead, focus on the network switches.

In usual cases, you’d send ethernet frames with numerous sender addresses to the target in a large quantity. This way, you’d consume the memory of the switch which stores the MAC address table, causing all the valid users to be pushed out of the network. This prevents the switch from sending incoming data to the destination.

15. What do you mean by the DHCP Rogue Server?

Ans: A rogue DHCP server is a DHCP server on a network that is no longer under the network staff’s or the administration’s control. It can be a router or model and will offer clients the default gateway, IP addresses, WINS servers, DNS servers, and other facilities.
In this case, if the rogue DHCP server passes information that differs from the real servers, the clients might face network access problems. It can also sniff all the traffic sent by the clients’ other networks and violate network security policies.

16. What Do you Mean by Enumeration?

Ans: In enumeration, you extract usernames, network resources, machine names, services and shares from a system. You create an active connection to the system and perform directed queries to gather information about your target which you can use to find the weak points in the target’s system security. You can conduct enumeration in intranet environments. It is a more robust attack technique than brute force attacks.

17. How Would you Prevent a Website from Getting Hacked?

Ans: I would save a website from getting hacked by using the following methods:

  • Sanitize and Validate user Parameters

I’ll sanitize and validate the user parameters before sending them to the database which would reduce the success of any SQL injection attack.

  • Use Firewall

I would use a firewall to mitigate traffic from suspicious IP addresses. This would save the website from simple DoS attacks.

  • Encrypt the Cookies

I would prevent cookie and session poisoning by encrypting the cookie content, associating cookies with a client IP address, and timing them out after a certain duration.

  • Validate and Verify User Input

I would validate and verify user input to prevent tampering.

  • Validate and Sanitize Headers

I would validate and sanitize headers to combat cross-site scripting (or XSS).

Note: This is among the most important ethical hacking interview questions and answers so you should prepare it very carefully.

18. What is NTP?

Ans: NTP stands for Network Time Protocol and it’s a networking protocol to synchronize clocks between computer systems. It supports synchronization over the Internet and local area networks. NTP is among the oldest components of the TCP/IP protocol suite.

19. What do you Mean by Keylogger Trojan?

Ans: A keylogger trojan or a keylogger virus tracks and logs everything you enter through your keyboard to give the attacker access to your personal data. As it tracks your every keystroke, the attacker can use its data to find your username and password. Keylogger Trojans are available for all kinds of computer devices including laptops, smartphones, and PCs.

20. What is Defacement?

Ans: In a defacement attack, you penetrate a website and replace its content with your own messages or make unexpected changes to files. Web defacements are the unauthorized modification of web pages. Usually, hacktivists such as Anonymous conduct these attacks by replacing the hosted messages on a website with their own.

21. What is Pharming?

Ans: Pharming is made of two words “phishing” and “farming”. Here the attacker installs malicious code on their target’s server or computer which directs the target to bogus websites without their consent or knowledge. For example, suppose you open the browser in your smartphone and a few suspicious websites open up as default automatically.

22. What Do you Mean by coWPAtty?

Ans: coWPAtty is a C-based tool that allows you to run brute-force dictionary attacks against WPA-PSK and audit pre-shared WPA keys. You can use this tool to find weak paraphrases while auditing WPA-PSK networks.

23. What are the Different Kinds of Hackers?

Ans: There are primarily three kinds of hackers:

  • White Hat Hackers

White hat hackers work with an organization to enhance its information security systems. They have the authority from the organization to find and exploit the weaknesses in their cybersecurity implementations. White hat hackers are also known as ethical hackers and they aim to find the weak spots of their organization’s cybersecurity implementations so they can strengthen the same.

  • Black Hat Hackers:

Black hat hackers are people who try to gain unauthorized entry into a network or system to exploit the same for malicious reasons. They don’t have any permission to exploit their target’s network or system and aim to cause damage to their target through one or multiple methods.

  • Grey Hat Hackers:

As the name suggests, grey hat hackers fall between the two categories we mentioned before. A grey hat hacker exploits a computer system or network without authority or permission (like a black hat) but they notify the owner or administrator about the issue for a fee. They might also extort the target and offer to fix the issue for a fee.

24. What is a Trojan Virus? What are its Different Types? 

Ans: A Trojan virus or a Trojan horse is a kind of malware disguised as legitimate software. Hackers use the trojan virus to gain access to their targets’ systems. They usually employ social engineering techniques such as phishing and pharming to install the virus on their target’s system.
The different types of Trojans are:

  • Trojan Backdoor
  • Trojan Rootkits
  • Trojan Droppers
  • Trojan Banker
  • Trojan-Downloader
  • Ransomware

25. Can you Name Different Kinds of Password Cracking Methods?

Ans: Yes, there are the following types of password cracking methods:

  • Guessing
  • Spidering
  • Shoulder surfing
  • Social engineering
  • Phishing
  • Rainbow table attacks
  • Rule-based attacks
  • Syllable attacks
  • Hybrid attacks
  • Brute forcing attacks
  • Dictionary attacks

26.What are the Different Kinds of Sniffing?

Ans: There are two kinds of sniffing:

Active sniffing: You use active sniffing in switch-based networks and determine whether the traffic would be locked, monitored and altered.

Passive sniffing: In passive sniffing, you lock the traffic but don’t alter it. You sniff through the hub. You use passive sniffing at the data link layer of the network.

27.What are the Different Enumerations?

Ans: Following are the various enumerations in ethical hacking:

  • Linux or Windows enumeration
  • DNS enumeration
  • SMB enumeration
  • SNMP enumeration
  • NTP enumeration


By using the above ethical hacking interview questions and answers, you can easily understand what to expect during the interview. They should help you figure out what kind of questions the recruiter would ask you. It would be best to understand the concepts instead of memorizing them when you’re preparing for a tech interview like this one. This way, you’d have a better grasp of the subject. 

If you’re interested in learning more about this field, check out our Executive PG Program in Cybersecurity. It would teach you the necessary skills for becoming a professional ethical hacker. 

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