Top 50 Most Asked Cyber Security Interview Questions for Freshers and Professionals

As the world is getting more and more digital, cybersecurity is very important in terms of data security, privacy, and critical systems. While this will be the case, many threats and vulnerabilities are finding their way into our technological world to be exploited by cybercriminals.

In this blog, we shall look into cybersecurity from both the elementary and advanced points of view and give a comprehensive set of interview questions and responses for candidates of various levels.

Below are answers to the top 50 cyber security interview questions suitable for freshers and experienced professionals.

Cyber Security Interview Questions for Freshers: Basic Cybersecurity Concepts

1. What do you know about Cyber Security?

Cybersecurity is basically the protection of computer systems, networks, programs, and data from digital attacks, unauthorised access, or theft and damage. With modern technologies, cybersecurity has been a major headache since most of our daily lives depend on digital systems. Therefore, from breached data to the attack of malicious software, the threat has grown quite high over the years. They often try to obtain sensitive information, destroy data, extort money from users, or disrupt normal business processes.

The aims of cyber attackers are mainly directed towards sensitive information being accessed, changed, or destroyed, extorting money from users, or interrupting the usual business processes. Cyber Security is also famous for computer security, information technology security, cybersecurity, etc. It’s used to measure the combat threats against networked systems and applications, whether those threats originate from inside or outside of an organisation.

We can split the two-word phrase cyber security into two words, namely cyber and security. Cyber means any technology that is connected to the internet, including networks, systems, applications, and data. The word security specifies protection of the systems, networks, applications, and information.

Also read: Types of cyber security

2. Discuss the main benefits of cyber security.

Following is a list of the main advantages of cyber security:

• Cyber security protects online businesses and transactions against ransomware, malware, online fraud, and phishing.
• It protects the end-users.
• It provides excellent security to data as well as networks.
• A Breach can have a longer recovery time.
• It helps prevent the leakage of sensitive information from unauthorised users.

3. What is Cyber Crime? Give some examples of Cyber Crime.

Cybercrime is just like any other crime, but it happens on the Internet. Here are some examples of cybercrime:

• Identity Theft
• Online Predators
• Hacking of sensitive information from the Internet
• BEC (“Business Email Compromise”)
• Ransomware
• Stealing intellectual property

4. Discuss the main objectives of Cyber Security.

The prime objective of cyber security is to protect data from cyber-attacks. It follows a principle called CIA Trio. The security sector concern is a triangle of three interconnected principles. The CIA model is designed to assist an organisation in developing policies about their information security architecture.

Three major components or elements of this CIA model are Confidentiality, Integrity, and Availability. Whenever a security breach occurs, it is because one or more of these principles is violated. Thus, the model provides a security paradigm for those who go through many aspects of IT security.

Let’s deal in detail with these three aspects of security:

• Confidentiality: Confidentiality can be said to make use of privacy so that unauthorised access to data is avoided. It ensures that the data are only accessible to those who have the authority to use the data and limits the access of others. It restricts vital information from being let out to the wrong hands. An example of confidentiality is data encryption, which is usually used to keep information private.
• Integrity: The Integrity principle comes into play to ensure the data is authentic, accurate, and protected from unauthorised threat actors or accidental user changes. It also states that the origin of information should be authentic. If any change in information is made, necessary precautions have to be taken in order to avoid corruption or loss of sensitive data and recover quickly in such an incident.
• Availability: The Availability principle ensures the information is constantly available and accessible to those who have access to it. It also makes sure that these accesses are not hindered by any kind of cyberattack or system breakdown.

5. What are the basic aspects of Cyber Security?

Given below are the main aspects of Cyber Security:

• Information security
• Network security
• Operational security
• Application security
• End-user security
• Business continuity planning

6. What is the difference between a threat, vulnerability and risk?

Generally, most people think that threat, vulnerability and risk mean the same, but there exist some important differences between them:

Threat:

A threat can be a form of hazard that may destroy or steal data, disrupt operations, or cause harm in general. Some examples of threats include malware, phishing, data breaches, even unethical employees, etc. Any kind of threat may be harmful to the organisation, so it is vital to understand the threats for developing effective mitigation and making informed cybersecurity decisions.

Vulnerability:

Vulnerability can be understood as a potential problem or flaw in hardware, software, personnel, or procedures that may cause harm to an organisation.

Following are some examples of vulnerabilities:

• Physical vulnerabilities: Publicly exposed networking equipment can be considered as a Physical vulnerability.
• Software vulnerabilities: Buffer overflow vulnerability in a browser.
• Human vulnerabilities: An employee vulnerable to phishing assaults.
• Zero-day vulnerability: It is the type of vulnerability for which a remedy is not available yet.

To cope with vulnerabilities, we have a methodology called Vulnerability management. It is the process of identifying, reporting, and repairing vulnerabilities.

Risk:

The combination of threat and vulnerability can be considered as risk. When we combine the probability of a threat with the consequence of vulnerability, that is known as a risk. It is the likeliness of a threat agent to exploit the vulnerability successfully.

The basic formula for calculating risk:

The risk management method is used to control and manage the risk. It is a procedure of identifying the list of all possible hazards, analysing their impact, and deciding the best action. It is an always running procedure that could be used to examine new threats and vulnerabilities on a regular basis. By using this method, we can avoid or minimise risks. We can also accept it or pass it to a third party according to the response chosen.

7. What is an Eavesdropping Attack?

Eavesdropping happens when a hacker intercepts, deletes, or modifies data transmitted between two devices. Sniffing or snooping are some alternative names for eavesdropping, which uses unprotected network interactions to acquire data exchanged between machines.

8. What is Data Leakage in the context of Cyber security?

Data leakage, in the context of Cyber security, can be explained as an unauthorised exposure of data to the outside of the secure network. Data leakage can take place via email, optical media, laptops, USB keys, etc.

9. Describe what a security audit is.

A security audit refers to the detailed examination of the implementation effectiveness of an organisation’s information system and its specific information on security policy, finding vulnerabilities and making recommendations.

Cyber Security Interview Questions for Freshers: Cryptography and Encryption

10. What is Cryptography?

Cryptography can be explained as a technique or practise for information protection from some third-party interactor, usually known as an adversary. It is mainly a method through which information and communication are made safe with the help of codes so that only the intended people would be able to read and process the data.

In cryptography, we also study a number of techniques for secure communication, mainly in order to protect sensitive data from third parties for whom the data isn’t intended.

11. What is the difference between Encryption and Hashing?

Encryption and Hashing are methods to convert readable data into an unreadable data format, but they differ in some ways.

12. What is the principal use of Hashing?

Hashing is required when we have to do comparisons of a huge amount of data. We can generate different hash values for different data, and we can also compare hashes.

Following is the list of some of the most critical uses of hashing:

• Hashing facilitates us to keep and find records of hashed data.
• Hashing can be used in cryptographic applications such as a digital signature.
• Hashing has numerous purposes, one of which is to create random strings. If one wants to prevent duplication of data.
• Hashing-Geometric hashing is the type of hashing in computer graphics that finds proximity issues in planes.

13. What do you understand by SSL encryption?

SSL (secure socket layer) ensures that data transferred between the web browsers and servers is kept secure. SSL makes the connection between your web server and your browser secure, keeping all data sent between them private and safe from attack.

14. What is Perfect Forward Secrecy?

Perfect Forward Secrecy is a style of encryption that creates a temporary exchange of secret keys between the server and the client. This is used mainly in calling up apps, websites, and messaging apps where user privacy is of primary importance. Every time the user commits an action, a new session key arises. This ensures that your data is uncompromised and protected from attacks.

Perfect Forward Secrecy technology generates a fresh encryption key each time a user starts a connection. In that case, if only the encryption key is compromised, the conversation gets leaked. If the user’s unique key gets compromised, the conversation will continue. More precisely, the encryption keys generated by Perfect Forward Secrecy keep you safe from attackers-twice as safe from attackers.

Cyber Security Interview Questions: Cyber Attacks and Prevention

15. What are the most common types of cyber security attacks?

Here are some of the common types of cyber security attacks:

• Phishing
• SQL Injection Attack
• Cross-Site Scripting (XSS)
• Brute Force
• Denial-of-Service (DoS)
• Session Hijacking
• Domain Name System Attack
• Malware
• Man-in-the-Middle Attacks

16. What do you understand by the MITM attack?

The MITM attack refers to the Man-in-the-Middle attack. As the name says, it is a form of attack where an unwanted third person/attacker intercepts communication going on between two persons. The main intention of MITM is to get classified or confidential information.

17. What is an XSS attack, and how can you prevent it?

The full form of an XSS attack is a Cross-Site Scripting attack. XSS is a cyberattack that enables hackers to inject malicious client-side scripts into web pages. The primary uses of XSS attacks include session hijacking, cookie robbery, DOM modification, remote code execution, server crash, and more.

We can use the following practices in order to prevent XSS attacks:

• Validate user inputs
• Sanitise user inputs
• Encode special characters
• Use Anti-XSS services/tools
• XSS HTML Filter

18. What is the difference between stored XSS and reflected XSS?

Difference between Stored and Reflected XSS Attacks:

 19. Outline the differences between active and passive cyber attacks.

Active Cyber Attack: An active attack is a type of attack wherein the attacker alters or tries to alter the content of the message. Active attacks pose a threat to integrity and availability. Active attacks may corrupt the system constantly and modify system resources. Most importantly, if there is an active attack, then the victim gets to know about the attack.

Passive Cyber Attack: In the passive attack, the attacker observes the message content or copies the message content. Passive attacks threaten confidentiality. Since it is a passive attack, there isn’t any damage to the system. Most importantly, while attacking passively, the victim is not notified about the attack.

20. What is XSS?

Cross-Site Scripting (XSS) is a web application security vulnerability that allows third-party entities to perform scripts on behalf of the web application inside the client’s browser. Cross-site scripting happens to be one of the most common security vulnerabilities in the Internet world nowadays. The exploitation of her XSS against users might result in account compromise, account deletion, privilege escalation, malware infection, etc.

21. What is a Distributed Denial of Service attack?

DoS describes a cyber-attack directed towards an individual computer or website such that the service is denied to its intended users. DoS interference occurs in the organisational network operations because it denies her access. In most cases, denial of service is achieved when the target machine or resource is bombarded with excessive requests, thereby overloading the system and preventing some or all legitimate requests from being satisfied.

22. What is a brute force attack?

This would involve an attacker employing a trial-and-error approach to derive the password or key for encryption by trying all possible permutations until the correct one is found.

23. What would you do if you found a breach of security?

Isolate the affected systems, contain the breach, notify appropriate parties, investigate the incident, fix vulnerabilities, and implement measures that will help avoid the breach from happening again.

Cyber Security Interview Questions: Networking and Firewalls

24. How is IDS different from IPS?

List of differences between IDS and IPS:

 25. Define the term IP blacklisting.

By adding a certain IP address to your blacklist, you may stop forged or unauthorised users from accessing your network. A blacklist simply shows a list of ranges or individual IP addresses to block.

26. What is a proxy firewall?

The proxy firewall checks the application-level information using the firewall proxy server. A server offering proxy firewall capabilities creates and executes a process on the firewall that echoes the services as if they were on the destination host.

In the Application layer, there are various protocols, such as HTTP protocol, used for sending and receiving web pages and SMTP, a protocol that sends e-mail messages on the Internet. In theory, a proxy server such as a Web Proxy Server is a process emulating the real HTTP service. The same goes with the FTP proxy server: the way his FTP service works is reflected.

27. What is a Firewall?

Firewalls are hardware or software-based network security devices that observe all incoming and outgoing traffic and accept, deny, or drop that particular traffic based on a defined set of security rules.

28. What do you understand by Unicasting, Multicasting, and Broadcasting? What is the difference between them?

Unicasting, Multicasting, and Broadcasting are three methods of sending data over the network.

Unicasting: Unicasting is used when information has to be transmitted from one user to a single receiver. In this case, it is for point-to-point communications.

Multicasting: In multicasting, data is transmitted from one or more sources to multiple destinations.

Broadcasting: Broadcasting is also referred to as one-to-all. In this process, only a single sender sends the data to multiple receivers. i.e., communication is done between a single user and several receivers. The best example of broadcasting is radio or TV broadcasting, where a single sender sends signals to many receivers.

29. What are the steps used to set up a firewall?

Various steps that may be followed in setting up a firewall include:

• Username/password: You need to change the default password for a firewall device that is needed for making the system secure.
• Remote administration: You need to turn off the remote administration feature.
• Port forwarding: You need to configure port forwarding appropriately that allows certain applications to work right, such as a web server or an FTP server.
• Disable the DHCP Server: If you set up a firewall on a network that currently has an active DHCP server, you could create a conflict if you haven’t disabled the firewall’s DHCP.
• Enable Logging: You must enable logging to troubleshoot firewall problems and/or possible attacks and know how to access logs.
• Security Policies: Under security policies, you will need to establish some sound and secure policies, ensuring the firewall is configured to implement those policies.

30. How to avoid ARP poisoning?

Here are the five ways of avoiding ARP Poisoning attacks:

Static ARP Tables: If one can confirm the proper mapping of the MAC addresses to the IP addresses, half the problem is solved. Yes, this can be done but it is very expensive to manage. In these tables, the ARP tables record all the associations, and each change in the network is carried out by manual updating. At the present day, for an organisation, it’s not feasible to manually do the updating of its ARP table on every host.

Switch Security: Most Ethernet switches have features that help reduce the chances of ARP poisoning attacks. This capability, further referred to as Dynamic ARP Inspection, aids in validating the ARP messages and drops packets that show any kind of malicious activity.

Physical Security: Controlling your organisation’s physical space is a very simple way of mitigating ARP poisoning attacks. Since ARP messages route only within the local network, this means an attacker has to be physically proximal to your victim’s network.

Network Isolation: A segmented network is much better than an unsegmented one; the range of ARP messages is no wider than the local subnet. That way, if an attack were to happen, parts of it would be affected and other parts safe. The attacks on one subnet will not affect devices that reside on other subnets.

Encryption: This does not help in preventing ARP poisoning but may reduce the potential damage of such an attack, should it happen. The credentials are stolen from across the network, similar to the MiTM attack.

Cyber Security Interview Questions: Authentication and Session Security

31. Define the term session hijacking.

Session hijacking refers to a security attack aimed at user sessions across a secure network. Currently, the easiest method for session hijacking is known as IP spoofing. In this method, an intruder utilises source-routed IP packets to inject commands into the active communications between two nodes over a network.

These commands facilitate an authenticated impersonation of one of the users. This type of attack is possible because authentication usually happens only at the beginning of a TCP session.

The types of session hijacking are as follows:

• CSRF Cross-site Request Forgery
• Cross-site Scripting
• IP spoofing
• Packet Sniffing

32. What is the Three-way handshake?

To create dependable connections, TCP employs a three-way handshake. Both ends of the connection have full-duplex synchronisation (SYN) and acknowledgement (ACK). These four flags are exchanged in three steps: SYN, SYN to ACK, and ACK.

33. What does two-factor authentication mean?

Two-factor authentication is the use of any two independent methods from a variety of authentication methods. Two-factor authentication is employed to ensure users’ access to secure systems and to enhance security. Two-factor authentication was originally implemented for laptops because of the basic security needs of mobile computing. Two-factor authentication complicates the act of unauthorised users using mobile devices to access secure data and systems.

Cyber Security Interview Questions: Penetration Testing and Security Measures

34. What do you mean by penetration testing?

This type of test is carried out for the detection of vulnerabilities, malicious items, flaws, and risks. It is done in order to make the security system of an organisation defend the IT infrastructure. It is an official helpful procedure. It forms one part of the ethical hacking process that specifically focuses only on penetration into the information system.

35. What is System Hardening?

All the vulnerabilities and flaws that a hacker can use to access your system constitute an attack surface, including default passwords, misconfigured firewalls, etc. The concept of hardening of a system consists of making it more secure by reducing the attack surface present in the design of this one. Hardening a system means reducing its attack surface, thereby making it more robust and secure. This is an integral part of system security practices.

36. What is Patch management in Cyber security, and how often should we do Patch management?

Patch management, in Cyber security, is the process of keeping the software of computers and network devices up to date to make them capable of resisting low-level cyber attacks. It is used in any software which is prone to technical vulnerabilities.

We should do patch management right after it is released. For instance, when there is a patch for Windows, it has to be applied on all machines immediately. The same goes with the network devices: we should do the patch management as soon as it is released. We need to stick with appropriate patch management in order to avail better security.

Cyber Security Interview Questions: Malware and Viruses

37. Explain Polymorphic viruses

“Poly” means many, and “morphic” means the shape. Therefore, polymorphic viruses, as the name would suggest, are the more complicated computer viruses that change shape as they proliferate because this may provide them a skip from being detected by antivirus programs. This is a self-encrypting virus that links a mutation engine with a self-propagating code.

A polymorphic virus has the following composition:

• Encrypted virus body mutation engine that produces random decryption routines.
• A polymorphic virus encryption occurs to both its mutation engine and the virus body. The virus decryption routine takes over control of the computer and decrypts the virus body and the mutation engine upon executing an infected program.
• Then, the control is transferred to the virus to find new programs to infect. Moreover, since the body of the virus is encrypted and the decryption routine also changes from infection to infection, it becomes tough for virus scanners to look for a fixed signature or fixed decryption routine.

38. What is a Botnet?

A botnet is shorthand for “robot network” and is a network of malware-infected computers under the control of a single attacker called a “bot herder”. Each individual machine under the control of a bot herder is a bot.

39. Explain the workings of a rootkit and how you would detect one.

A rootkit is a certain form of malware used to gain unauthorised access in a certain manner to a computer or network to other malicious actors. Detection comes through the usage of anti-rootkit-specific tools and monitoring for suspicious system behaviour.

Cyber Security Interview Questions for Freshers: Phishing and Social Engineering

40. What do you understand by Shoulder Surfing?

Shoulder surfing is a kind of physical attack by which fraudsters peep physically at people’s screens to cheat while they type sensitive information in a semi-public area.

41. Define social engineering attack.

Social engineering can be defined as the manipulation of individuals to perform a certain activity that might be or is not in the best interest of the target. This involves information retrieval, access, and one’s desired goal to execute an action. It manipulates people by tricking them. A phone call supported by a survey or a quick internet search may bring updates on birthdays and anniversaries and arm you with that information. That can be enough information to create a list with which to attack passwords.

42. Who are black hat hackers and white hat hackers?

White Hat Hacker: A white hat hacker is a certified or licensed hacker who works for governments and organisations through the process of penetration testing and recognising gaps in cybersecurity. It also ensures protection against harmful cybercrime.

Black Hat Hackers: They are also called crackers. The black hat hackers might access your system without any authorisation and kill your precious data. Their attacking method involves the use of some ordinary hacking techniques that one learns in the earlier stages. They are dealt with as criminals and can be caught very easily because of their vicious activities.

43. Differentiate between spear phishing and phishing.

Phishing: It is an electronic mail attack where the user’s sensitive information is fraudulently attempted to be discovered by an attacker through the use of some electronically communicated message pretending to come from relevant and trusted organisations. Attackers craft such emails very carefully, target certain groups, and click the links to install malicious code on your computer.

Spear phishing: Spear phishing is an email attack that involves highly focused targets on particular individuals or organisations. In Spear, a phishing attacker lures a target into clicking on a malicious link and instals malicious code in order to retrieve sensitive information from the target’s system or network.

Cyber Security Interview Questions: Miscellaneous Technical Knowledge

44. What is called a honeypot, and what are its types?

The honeypot is a networked system that acts as bait in detecting and investigating hacker tactics and types of attacks. It normally performs the role of a potential target on the Internet and informs the defenders about unauthorised access to information systems.

Based on usage, the honeypots are classified as:

1. Honeypots for Research: These are set up by the researchers to study the hacking attacks and find out various means to prevent such hacking.
2. Production Honeypots: Production honeypots are deployed along with servers on the production network. These honeypots serve as a front-end trap for the attackers composed of dummy information, thus providing time to the administrators for the patching of all vulnerabilities in actual systems.

45. What is a Null Session?

The null session attacks existed ever since the wide usage of Windows 2000. However, normally, such an attack is not considered by the system administrator while taking measures to secure a network.

The consequences can just be imagined with such a kind of attack because this provides all that a hacker needs to obtain information for remotely accessing your system.

An attack of this type is harder to conduct when the customer is operating a newer version of the OS, but still, the most common are Windows XP and Windows Server 2003.

46. What is DNS?

DNS-It basically stands for a domain name translation system, which translates names into IP addresses used by browsers to load web pages. Every device over the internet has an IP address, and other devices use it to identify it. We can say in simple language that DNS defines the service of the network.

47. What is a VPN?

VPN stands for Virtual Private Network. A virtual private network (VPN) is the technology that creates a safe and encrypted connection over an insecure one, such as the Internet. In other words, a virtual private network is a method of connecting (or extending) a private network using a public network (like the Internet). The name itself suggests it is a virtual “private network”. One can be a user at some remote location in a local area network. Establish a secure connection using a tunnelling protocol.

48. How does email work?

When someone sends an e-mail by using the e-mail program, it spontaneously gets rerouted to some basic e-mail transfer protocol. During this protocol, the recipient’s e-mail address belongs to either some different domain name or to the same domain name as the sender has (Gmail or Outlook).

After that, e-mail will be stored on the server, and later, he will send it using the POP or IMAP protocol. After that, if the recipient has a different domain name address, then the SMTP protocol communicates with the DNS (Domain Name Server) for different addresses that the receiver is using. Then, the sender’s SMTP communicates with the receiver’s SMTP, and the receiver’s SMTP performs the communication.

The email, this way, reaches the SMTP of the recipient. If some network traffic issues prevent both the sender’s and recipient’s SMTPs from communicating with each other, the outgoing emails will be queued at the SMTP of the recipient and finally be received by him. Also, the message is returned to the sender as not delivered in case the message remains in the queue for too long due to appalling conditions.

49. What is a block cipher?

Block Cipher It is a type of cipher that converts plaintext into ciphertext using one block of plaintext at a time. Using 64-bit or 64-bit or higher. The block ciphers are simple in complexity. The block ciphers using modes of the algorithm are ECB (Electronic Code Book) and CBC (Cipher Block Chaining).

50. What do you understand by Port Scanning?

Port scanning is the technique that administrators and hackers use to identify the open ports and services available on a host. The hackers use this technique to gather information, which will be helpful in finding flaws and further exploiting the vulnerabilities, whereas the administrators use this technique to verify the security policies of the network.