Top 20 Cyber Security JOB interview Questions 

1. What is pen testing?

Penetration testing, also known as pentesting, is the practice of simulating a cyber attack on a computer system, network, or web application to identify vulnerabilities that an attacker could exploit. Pentesters, also known as ethical hackers, use a variety of tools and techniques to attempt to gain unauthorized access to systems and networks, and then report any vulnerabilities they find to the system owner so that they can be fixed.

2. What is the CIA triad?

The CIA triad is a model for ensuring the security of information systems. It consists of three components: confidentiality, integrity, and availability.

• Confidentiality refers to the protection of information from being accessed by unauthorized individuals or systems.
• Integrity refers to the protection of information from being modified or corrupted in an unauthorized way.
• Availability refers to the guarantee that authorized users can access the information when they need to.

Together, these three components form the basis of information security and are considered the key factors in ensuring the security of any information system.

3. What is xss? what are the three types?

Cross-Site Scripting (XSS) is a type of vulnerability that allows attackers to inject malicious code into a website or web application. This code is executed by the victim’s web browser, allowing the attacker to steal sensitive information, perform unauthorized actions, or redirect the victim to a different website.

There are three main types of XSS:

1. Stored XSS: This type of XSS involves injecting malicious code into a website or web application’s database, where it is stored and executed whenever the vulnerable page is loaded.
2. Reflected XSS: This type of XSS involves injecting malicious code into a website or web application through a user input, such as a search query or a comment form. The code is then reflected back to the user, and executed by their web browser.
3. DOM-based XSS: This type of XSS involves injecting malicious code into a website or web application through the Document Object Model (DOM), rather than the server-side code. This allows the attacker to manipulate the website or web application in real-time, without the need for the code to be stored or reflected back to the user.

XSS attacks can be dangerous, as they allow attackers to steal sensitive information, perform unauthorized actions, or redirect victims to malicious websites. It is important for web developers to take steps to prevent XSS vulnerabilities in their applications.

4. What is a CSRF attack and how can it be prevented ?

A Cross-Site Request Forgery (CSRF) attack is a type of vulnerability that allows an attacker to perform unauthorized actions on a website or web application on behalf of a victim. This is done by tricking the victim’s web browser into sending a request to the website or web application, without the victim’s knowledge or consent.

For example, if a victim is logged into their online banking account, an attacker could craft a malicious link or form that causes the victim’s web browser to send a request to transfer money out of their account, without the victim knowing about it.

To prevent CSRF attacks, web developers can use a number of techniques, such as:

• Including a unique, unpredictable token in all forms and AJAX requests, which is checked on the server side to verify that the request is legitimate.
• Using the HTTP Referer header to verify that requests are coming from the same website or domain.
• Restricting the HTTP methods that are allowed for certain URLs or forms, to prevent unexpected or unauthorized requests.
• Implementing strict same-origin policies, to prevent malicious websites or applications from accessing the victim’s web browser.

By implementing these and other measures, web developers can protect their applications and users from CSRF attacks.

5. How does traceroute or tracert work?

Traceroute, also known as tracert on some operating systems, is a network diagnostic tool that shows the route that a packet of data takes from its source to its destination. It does this by sending a series of packets with increasing time-to-live (TTL) values, and measuring the time it takes for each packet to reach its destination or to be returned as undeliverable.

Each packet is sent with a TTL value of 1, then 2, then 3, and so on, until it reaches the destination or the maximum TTL value is reached. As the packets are forwarded by each network device along the way, the TTL value is decremented by 1. When the TTL value reaches 0, the packet is discarded and an error message (ICMP Time Exceeded) is returned to the sender.

Traceroute uses these error messages to determine the path that the packets took, and the amount of time it took for each packet to be returned or to reach its destination. This information is then displayed to the user, showing the series of network devices that the packets traversed, along with the round-trip time for each hop.

Traceroute can be useful for troubleshooting network problems, such as slow connections or connectivity issues, by showing where the bottleneck or problem is occurring along the route. It can also be used to determine the physical distance between the source and destination, or to find the location of a particular network device.

6. What are some ways to avoid brute force hacks?

A brute force attack is a type of cyber attack that involves trying every possible combination of characters or passwords in order to guess a password or encryption key. This can be a time-consuming process, but with the help of powerful computers and sophisticated algorithms, it is possible for attackers to try millions or even billions of combinations in a short amount of time.

To avoid brute force attacks, there are a few steps that you can take:

• Use strong, complex passwords that are difficult for attackers to guess. This means using a mix of upper and lowercase letters, numbers, and special characters, and avoiding common words or phrases.
• Use two-factor authentication (2FA) or multi-factor authentication (MFA) whenever possible. This adds an extra layer of security, requiring the user to provide a second piece of information (such as a code sent to their phone) in addition to their password.
• Use password managers to store your passwords securely. This allows you to use different, complex passwords for each account, without having to remember them all.
• Implement rate-limiting or brute-force detection mechanisms on your website or web application. This means setting limits on the number of failed login attempts that are allowed within a certain time period, and blocking or alerting the user if they exceed these limits.

By following these steps, you can make it much more difficult for attackers to guess your password or encryption key through a brute force attack.

7. What are the common ports to focus on during penetration testing?

During a penetration test, also known as a “pen test” or “ethical hacking,” the tester typically focuses on a number of common network ports that are known to be vulnerable to attack. These ports are typically associated with specific services or protocols, and are commonly used by attackers to gain unauthorized access to a system or network.

Some of the common ports that are often targeted during a pen test include:

• Port 21 (FTP): Used for the File Transfer Protocol, this port is often targeted by attackers to gain access to files on a remote server.
• Port 22 (SSH): Used for secure shell access, this port is often targeted by attackers to gain remote access to a server or network device.
• Port 23 (Telnet): Used for remote terminal access, this port is often targeted by attackers to gain access to a device’s command line interface.
• Port 25 (SMTP): Used for sending email, this port is often targeted by attackers to send spam or phishing emails.
• Port 53 (DNS): Used for domain name resolution, this port is often targeted by attackers to redirect traffic or perform DNS cache poisoning.
• Port 80 (HTTP): Used for the World Wide Web, this port is often targeted by attackers to gain access to web applications or websites.
• Port 443 (HTTPS): Used for secure web communication, this port is often targeted by attackers to gain access to secure web applications or websites.

By focusing on these and other commonly-used ports, penetration testers can identify and exploit vulnerabilities that may be present on a system or network. This information can then be used to improve the security of the system and protect it from real-world attacks.

8. We have a firewall in place. Do we still need network penetration testing if we have a Firewall?

While a firewall can provide an important layer of security for your network, it is not a silver bullet and cannot protect against all types of attacks. A firewall is typically designed to block or allow traffic based on rules that are set by the administrator, such as the source and destination IP addresses, the port number, or the protocol.

However, there are many ways that attackers can bypass or exploit a firewall, such as:

• Using legitimate ports and protocols that are allowed by the firewall rules.
• Manipulating the packet headers or payloads to bypass the firewall rules.
• Exploiting vulnerabilities in the firewall software or hardware itself.
• Using social engineering or phishing attacks to trick the administrator into allowing unauthorized traffic.

For these reasons, it is important to perform network penetration testing even if you have a firewall in place. A pen test can help identify vulnerabilities and weaknesses in your network that a firewall might not be able to protect against. This information can then be used to improve the security of your network and protect it from real-world attacks.

9. What are different open-source penetration testing tools?

There are many open source penetration testing tools available that can be used to test the security of a system or network. Some of the most popular open source tools include:

• Metasploit: A powerful framework for developing and executing exploit code.
• Nmap: A network mapping and scanning tool that can be used to discover hosts and services on a network.
• Wireshark: A network protocol analyzer that can be used to capture and analyze network traffic.
• Aircrack-ng: A suite of tools for wireless network security testing, including packet capture and WEP/WPA/WPA2 cracking.
• John the Ripper: A password cracking tool that can be used to test the strength of passwords and identify weak or commonly-used passwords.
• Maltego: A tool for performing forensic and intelligence analysis on a network.
• Burp Suite: A web application security testing platform that includes tools for spidering, scanning, and attacking web applications.
• sqlmap: A tool for automating the detection and exploitation of SQL injection vulnerabilities.

These are just a few examples of open source penetration testing tools that are available. There are many other tools that can be used for different purposes, such as network analysis, password cracking, exploit development, or web application testing.

10. What is the difference between asymmetric and symmetric encryption?

Asymmetric encryption and symmetric encryption are two different types of encryption algorithms that are used to secure data and protect it from unauthorized access. The main difference between the two is the way that they use keys to encrypt and decrypt the data.

In symmetric encryption, the same key is used to both encrypt and decrypt the data. This means that the sender and receiver must both have a copy of the same key in order to communicate securely. Symmetric encryption is fast and efficient, but it can be difficult to securely share the key between the sender and receiver.

In asymmetric encryption, also known as public-key encryption, each user has a pair of keys: a public key and a private key. The public key is used to encrypt the data, and can be shared freely with anyone. The private key is used to decrypt the data, and must be kept secret by the owner. Asymmetric encryption is more secure than symmetric encryption, but it is also slower and more resource-intensive.

In practice, many encryption systems use a combination of both symmetric and asymmetric encryption to achieve the best balance of security and performance. For example, a message may be encrypted using a symmetric key, and then the symmetric key itself may be encrypted using the recipient’s public key. This allows the message to be securely transmitted and decrypted by the recipient using their private key.

11. Explain what is Buffer Overflow ?

A buffer overflow is a type of vulnerability that occurs when a program or process attempts to write more data to a fixed-size buffer or memory area than it is capable of holding. This can cause the buffer to overflow, or “spill” data into adjacent memory areas, potentially overwriting or corrupting other data or code.

Buffer overflows are often caused by programming errors, such as failing to properly check the length of user input or failing to allocate enough memory for a buffer. They can also be caused by attacks, such as sending a large amount of data to a program or process in order to overflow a buffer and execute malicious code.

Buffer overflows can be dangerous, as they can allow attackers to gain unauthorized access to a system, execute arbitrary code, or cause the program or process to crash. They can also be difficult to detect and prevent, as they often involve low-level details of the program or process’s memory management.

To prevent buffer overflows, developers can follow best practices for secure coding, such as properly checking and validating user input, allocating enough memory for buffers, and using safe, memory-safe languages and libraries. They can also use tools and techniques such as static analysis, runtime analysis, and fuzz testing to detect and prevent buffer overflows in their code.

12. What type of tools are there out there for packet sniffing?

Packet sniffing is the practice of capturing and analyzing network traffic to identify and diagnose problems, or to gain unauthorized access to sensitive information. There are a number of tools that can be used for packet sniffing, depending on the specific needs and goals of the user.

Some of the most common types of packet sniffing tools include:

• Network analyzers or protocol analyzers: These are specialized tools that can be used to capture, display, and analyze network traffic in real-time. They often include features such as filtering, decoding, and reassembling of packets, as well as protocol-specific analysis and reporting. Examples of network analyzers include Wireshark, tcpdump, and EtherApe.
• Intrusion detection and prevention systems (IDPS): These are security tools that are designed to monitor network traffic for suspicious or malicious activity, and take action to prevent or block it. They often include packet sniffing capabilities, as well as other security features such as intrusion detection algorithms, signature-based detection, and anomaly detection. Examples of IDPS tools include Snort, Suricata, and Bro.
• Wireless sniffers: These are tools that are specifically designed to capture and analyze wireless network traffic, such as Wi-Fi or Bluetooth. They often include features such as channel hopping, packet injection, and decryption of encrypted traffic. Examples of wireless sniffers include Kismet, Aircrack-ng, and WifiPhisher.

In addition to these specialized tools, many general-purpose network monitoring and management tools also include packet sniffing capabilities, such as network management systems (NMS), network performance monitors (NPM), and network flow analyzers.

13. What is the difference between Authentication and Authorization?

Authentication and authorization are two related but distinct concepts in the field of computer security. Authentication is the process of verifying the identity of a user, device, or system, to ensure that they are who or what they claim to be. This is typically done by requiring the user to provide some form of credentials, such as a username and password, a token or key, or a biometric identifier.

Authorization, on the other hand, is the process of granting or denying access to resources or actions based on the authenticated identity of the user, device, or system. This is typically done by checking the authenticated identity against a set of permissions or rules, to determine what the user is allowed to do or access.

For example, when a user logs into a website or web application, the website first authenticates the user by verifying their username and password. Once the user has been authenticated, the website checks the user’s permissions or roles to determine what actions or resources they are allowed to access. This is the authorization step.

In summary, authentication is about verifying the identity of the user, while authorization is about determining what the user is allowed to do or access based on their identity. These two concepts are often used together to provide secure access control to systems and resources.

14. What are the Phases of a Network Penetration Test? or What are the 5 steps in the methodology of a Hacker?

The methodology or process of a network penetration test, also known as a “pen test” or “ethical hacking,” typically follows a set of well-defined phases or steps. These phases are designed to systematically identify and exploit vulnerabilities in a network or system, and provide actionable recommendations for improving its security.

The five main phases of a network penetration test are:

1. Reconnaissance: In this phase, the tester gathers information about the target network or system, such as its IP addresses, domain names, open ports, and services. This can be done through a variety of methods, such as network scanning, social engineering, or public information sources. The goal of this phase is to identify potential targets and entry points for further testing.
2. Scanning: In this phase, the tester uses specialized tools and techniques to scan the target network or system, looking for vulnerabilities or weaknesses that can be exploited. This can include network scanning, port scanning, vulnerability scanning, or protocol analysis. The goal of this phase is to identify specific vulnerabilities or entry points that can be used to gain access to the system or network.
3. Exploitation: In this phase, the tester attempts to exploit the vulnerabilities or entry points that were identified in the previous phases, in order to gain unauthorized access to the system or network. This can involve using pre-built exploit code or tools, developing custom exploit code, or using social engineering techniques. The goal of this phase is to gain access to the system or network and demonstrate the impact of the vulnerabilities that were identified.
4. Maintaining Access: In this step, the hacker works to maintain their unauthorized access to the system or network, in order to continue stealing or misusing sensitive information. This can involve using techniques such as privilege escalation, persistence mechanisms, or network tunneling to maintain their foothold on the system or network. The goal of this step is to maintain access to the system or network for as long as possible, without being detected or blocked.
5. Covering Tracks: In this step, the hacker attempts to cover their tracks and hide their activities from the system or network administrator, in order to avoid detection and prosecution. This can involve deleting logs, modifying files, or using encryption to hide their actions.

15. How do you test for Blind SQL injection?

There are several ways to test for Blind SQL injection, but the most common approach is to use a series of carefully crafted SQL statements to determine if the application is vulnerable to injection. This is typically done by injecting carefully crafted input into the application and observing its behavior. For example, you could try inserting a single quote (‘) character into a text field in the application and see if the application behaves abnormally, such as displaying an error message or behaving unexpectedly.

If you suspect that an application is vulnerable to Blind SQL injection, it is important to verify this with a thorough testing process. This may involve manually testing the application with various inputs, or using automated tools to perform the testing for you. It is important to test all input fields and all user-controllable inputs, as well as any hidden or obscured fields that may be susceptible to injection.

Once you have determined that an application is vulnerable to Blind SQL injection, the next step is to exploit the vulnerability. This can be done in a number of ways, but the most common approach is to use a tool or script that automates the injection process. These tools can be used to extract sensitive information from the database, such as user passwords or other sensitive data.

It is important to note that testing for and exploiting Blind SQL injection vulnerabilities can be illegal and can have serious consequences. It is important to only perform these activities on systems that you have permission to test, and to follow all applicable laws and regulations.

16. Which is your favourite attack?

To be answered by You Follow up question related to the attack you said.

17. What kind of Methods are there in HTTP Request?

HTTP requests can use several different methods to indicate the desired action to be performed on the specified resource. The most commonly used HTTP methods are:

• GET: This method is used to retrieve information from the specified resource. It is the most commonly used HTTP method, and is used to retrieve web pages and other resources from a web server.
• HEAD: This method is similar to GET, but it only retrieves the HTTP headers, without the body of the response. It is often used to check the status or availability of a resource, or to retrieve metadata about a resource.
• POST: This method is used to submit data to the specified resource. It is often used to submit a web form, or to upload a file to a server.
• PUT: This method is used to replace the contents of the specified resource. It is often used to upload a new version of a file to a server.
• DELETE: This method is used to delete the specified resource. It is often used to delete a file from a server.
• TRACE: This method is used to perform a message loop-back test along the path to the target resource. It is often used for debugging or diagnostic purposes.
• OPTIONS: This method is used to describe the communication options for the target resource. It is often used to determine the capabilities of a server, or to check if a specific feature is supported.
• CONNECT: This method is used to establish a tunnel to the server identified by the target resource. It is often used in conjunction with HTTPS to establish a secure connection to the server.

18. List the benefits that can be provided by an intrusion detection system.

An intrusion detection system (IDS) can provide several benefits, including:

1. Improved security: An IDS can monitor network traffic for suspicious activity and alert security personnel when potential threats are detected. This can help prevent or mitigate security breaches and protect against cyber attacks.
2. Real-time threat detection: An IDS can detect threats in real-time, allowing security personnel to respond quickly and effectively to potential threats.
3. Increased visibility: An IDS can provide visibility into network activity, allowing security personnel to better understand what is happening on the network and take appropriate action.
4. Compliance: Some IDSs are designed to help organizations comply with industry regulations and standards, such as PCI DSS and HIPAA.
5. Customizable alerts: An IDS can be configured to generate alerts based on specific security policies and thresholds, allowing organizations to tailor their security posture to their unique needs and requirements.
6. Enhanced network performance: An IDS can monitor network performance and identify potential bottlenecks or other performance issues, allowing organizations to optimize their network for better performance.
7. Improved incident response: An IDS can provide detailed information about security incidents, allowing organizations to respond more effectively and minimize the impact of security breaches.

19. How SSL/TLS works?

SSL/TLS is a cryptographic protocol that is used to provide secure communication over a computer network. It is typically used to secure communication between a web server and a web client, such as a web browser.

The SSL/TLS process typically works as follows:

1. The client initiates a connection to the server by sending a message requesting a secure connection.
2. The server responds by sending its SSL/TLS certificate, which contains its public key and other information about the server’s identity.
3. The client verifies the server’s certificate and extracts the server’s public key.
4. The client and server then use the server’s public key to establish a shared secret key, which is used to encrypt and decrypt messages sent between the two parties.
5. Once the shared secret key has been established, the client and server can communicate securely over the network, using the secret key to encrypt and decrypt their messages.
6. The SSL/TLS protocol also includes mechanisms for detecting tampering or other attacks on the communication channel, such as message authentication codes and checksums.

Overall, the SSL/TLS protocol provides secure communication by encrypting messages, authenticating the identity of the server and client, and detecting potential tampering or attacks on the communication channel.

20. What is the difference between Threat / Vulnerability / Risk?

Threat, vulnerability, and risk are related but distinct concepts. A threat is a potential source of harm or adverse impact. A vulnerability is a weakness or gap in security that can be exploited by a threat. Risk is the likelihood that a threat will exploit a vulnerability, and the potential impact of that exploitation. In other words, a threat is something that can cause harm, a vulnerability is a weakness that can be exploited, and risk is the potential for harm to occur.