Certified Ethical Hacker (CEH V12) - Interview Question Answers

Certified Ethical Hacker v12 - CEHv12 Interview Questions - For Intermediate

1. What is a backdoor in computer security?

A backdoor is a method of bypassing normal authentication procedures to gain unauthorized access to a computer system or encrypted data.

2. Define 'phishing' and how it can be prevented.

Phishing is a type of social engineering attack often used to steal user data, including login credentials and credit card numbers. It can be prevented through user education, spam filters, and security solutions that scan for malicious links or attachments.

3. What are the main differences between a virus and a worm?

A virus is a malicious code that attaches itself to clean files and spreads through manual user intervention, while a worm is a standalone malware that replicates itself to spread to other computers, often over a network.

4. What is the purpose of a rootkit?

A rootkit is designed to remotely control or alter the functions of a system without being detected by users or security programs.

5. Explain 'man-in-the-middle' (MitM) attacks.

MitM attacks involve an attacker secretly relaying and possibly altering the communication between two parties who believe they are directly communicating with each other.

6. What is two-factor authentication (2FA), and why is it important?

Two-factor authentication is a security process in which users provide two different authentication factors to verify themselves. It's important because it adds an additional layer of security, making it harder for attackers to gain access to a person's devices or online accounts.

7. What does 'network sniffing' mean?

Network sniffing is the process of monitoring and capturing all data packets passing through a given network using sniffing tools. It is used both for malicious purposes and for network management.

8. How do firewalls prevent unauthorized access?

Firewalls act as a barrier between secured and controlled internal networks that can be trusted and untrusted outside networks. They do this by filtering incoming and outgoing traffic based on an organization's previously established security policies.

9. What is a Zero Day vulnerability?

A Zero Day vulnerability refers to a security hole in software that is unknown to the vendor. This vulnerability can be exploited by hackers before the vendor becomes aware and hurries to fix it.

10. What is the purpose of using a proxy server?

A proxy server acts as a gateway between users and the internet. It provides increased security, administrative control, and caching services to improve performance.

11. Describe what 'spoofing' is and give an example.

Spoofing is a fraudulent or malicious practice in which communication from an unknown source is disguised as being from a known, trusted source. Email spoofing and IP spoofing are common examples.

12. What is risk assessment in cybersecurity?

Risk assessment is the process of identifying, analyzing, and evaluating risk. It helps to identify potential threats to an organization's information assets and infrastructure, and to determine what measures should be taken to reduce or eliminate the risk.

13. What are the differences between white box, black box, and grey box testing?

White box testing is testing where the tester has access to all the background and system implementation information. Black box testing is where the tester knows nothing about the system. Grey box testing is in-between, with limited knowledge of the system.

14. Can you explain what a security audit is?

A security audit is a systematic evaluation of the security of a company's information system by measuring how well it conforms to a set of established criteria.

15. What is 'credential stuffing'?

Credential stuffing is a type of cyberattack where stolen account credentials, typically consisting of lists of usernames and/or email addresses and the corresponding passwords, are used to gain unauthorized access to user accounts through large-scale automated login requests directed against a web application.

16. What role does encryption play in cybersecurity?

Encryption is essential in cybersecurity as it secures data by converting it into unreadable code that can only be deciphered by someone with the correct decryption key, thereby protecting sensitive information from unauthorized access.

17. What is an SSL certificate, and why is it important?

An SSL (Secure Sockets Layer) certificate is a digital certificate that provides authentication for a website and enables an encrypted connection. It's important because it ensures that all data transmitted between the web server and browser remains encrypted and private.

18. Define 'brute force attack' and how it can be mitigated.

A brute force attack is a trial-and-error method used to obtain information such as a user password or personal identification number (PIN). It can be mitigated by implementing account lockout policies, CAPTCHA, and limiting login attempts.

19. What is 'data leakage'?

Data leakage is the unauthorized transmission of data from within an organization to an external destination or recipient. It can occur through various channels, such as emails, physical removal of data, or unauthorized network connections.

20. Explain the concept of 'penetration testing' depth levels.

Penetration testing depth levels refer to the extent and depth of a penetration test. It can range from shallow (testing with limited information and scope) to deep (comprehensive testing involving full knowledge of the system, detailed exploration of vulnerabilities, and exploitation of those vulnerabilities).

Certified Ethical Hacker v12 - CEHv12 Interview Questions - For Advanced

1. What is SQL Injection and how can it be prevented?

SQL Injection is a type of cyber attack where an attacker injects malicious SQL code into a query through user input. This allows the attacker to manipulate the query, potentially accessing, modifying, or deleting data in the database.

Prevention:

• Parameterized Queries: Use parameterized queries (prepared statements) to separate SQL code from user input.
• Stored Procedures: Implement stored procedures to encapsulate SQL code and control user input.
• Input Validation: Validate and sanitize all user inputs to ensure they do not contain malicious SQL.
• Least Privilege: Apply the principle of least privilege to database accounts, restricting their access to only what is necessary.
• Error Handling: Avoid displaying database errors to users, as these can reveal vulnerabilities.

2. Explain the difference between symmetric and asymmetric encryption.

Symmetric Encryption:

• Uses a single key for both encryption and decryption.
• Faster and more efficient for large amounts of data.
• The key must be securely shared between parties, which can be a challenge.

Asymmetric Encryption:

• Uses a pair of keys: a public key for encryption and a private key for decryption.
• Slower compared to symmetric encryption due to its complexity.
• Solves the key distribution problem since the public key can be freely shared.

3. What is a Man-in-the-Middle (MitM) attack and how can it be mitigated?

A Man-in-the-Middle (MitM) attack occurs when an attacker intercepts and potentially alters the communication between two parties without their knowledge. This can lead to data breaches, eavesdropping, and manipulation of the information exchanged.

Mitigation:

• Encryption: Use strong encryption protocols like TLS/SSL to secure communications.
• Authentication: Implement mutual authentication to ensure both parties verify each other's identity.
• Secure Networks: Avoid using unsecured public Wi-Fi for sensitive communications.
• Intrusion Detection Systems: Deploy IDS to detect unusual traffic patterns indicative of MitM attacks.
• Public Key Infrastructure (PKI): Utilize PKI for managing digital certificates and keys.

4. Describe the OWASP Top 10 and its significance.

The OWASP Top 10 is a list of the most critical web application security risks, compiled by the Open Web Application Security Project (OWASP). It serves as a guideline for developers and security professionals to prioritize and mitigate common vulnerabilities.

Significance:

• Awareness: Increases awareness of prevalent security issues among developers and stakeholders.
• Standardization: Provides a standardized reference for security testing and compliance.
• Improved Security Posture: Encourages the adoption of best practices, leading to more secure applications.
• Training and Education: Serves as a basis for training programs in web application security.

5. What are the steps involved in a typical penetration testing process?

• Planning and Preparation: Define the scope, objectives, and rules of engagement for the penetration test. Obtain necessary permissions and gather preliminary information about the target.
• Information Gathering: Collect data about the target using passive and active reconnaissance techniques, including network scanning, social engineering, and open-source intelligence.
• Vulnerability Analysis: Identify and prioritize potential vulnerabilities in the target systems using automated tools and manual techniques.
• Exploitation: Attempt to exploit identified vulnerabilities to gain unauthorized access or control over the target systems.
• Post-Exploitation: Assess the potential impact of successful exploitation and gather additional information that could lead to further attacks.
• Reporting: Document findings, including discovered vulnerabilities, successful exploits, and recommendations for remediation.
• Remediation and Retesting: Work with the target organization to address identified vulnerabilities and perform retesting to ensure effective mitigation.

6. What is a zero-day vulnerability, and how should organizations respond to it?

A zero-day vulnerability is a security flaw in software that is unknown to the vendor and has no available patch or fix. These vulnerabilities are particularly dangerous because they can be exploited by attackers before the vendor becomes aware and releases a patch.

Response:

• Threat Intelligence: Stay informed about potential zero-day vulnerabilities through threat intelligence feeds and security advisories.
• Network Segmentation: Implement network segmentation to limit the impact of an exploit.
• Intrusion Detection and Prevention: Deploy IDS/IPS to detect and block suspicious activities associated with zero-day exploits.
• Patch Management: Apply patches and updates as soon as they become available.
• Incident Response Plan: Have an incident response plan in place to quickly address and contain any breaches resulting from zero-day exploits.

7. Explain the concept of lateral movement in the context of a cyber attack.

Lateral movement refers to the techniques used by attackers to move within a network after gaining initial access. The goal is to explore the network, escalate privileges, and reach critical assets or data.

Techniques:

• Credential Dumping: Extracting credentials from compromised systems to access other systems.
• Pass-the-Hash: Using hashed passwords to authenticate to other systems without cracking the hash.
• Remote Execution: Executing commands on remote systems using tools like PsExec or PowerShell.
• Tunneling: Creating tunnels through compromised systems to reach other network segments.

8. What is a honeypot and how is it used in cybersecurity?

A honeypot is a decoy system or network resource designed to attract and monitor malicious activities. It serves as a trap for attackers, diverting them from critical systems and gathering intelligence on their tactics.

Uses:

• Threat Detection: Identifying and analyzing attack patterns and techniques.
• Deception: Diverting attackers away from valuable assets.
• Research: Studying attacker behavior and developing better defenses.
• Training: Providing a controlled environment for security training and testing.

9. What is cross-site scripting (XSS) and what are its types?

Cross-site scripting (XSS) is a type of security vulnerability that allows attackers to inject malicious scripts into web pages viewed by other users. This can lead to data theft, session hijacking, and other malicious activities.

Types:

• Stored XSS: Malicious script is permanently stored on the target server (e.g., in a database) and executed when users view the affected page.
• Reflected XSS: Malicious script is reflected off a web server in a response, typically through a URL parameter, and executed in the user's browser.
• DOM-based XSS: Malicious script is executed as a result of modifying the Document Object Model (DOM) in the user's browser.

Prevention:

• Input Sanitization: Sanitize and validate all user inputs.
• Output Encoding: Encode outputs to ensure scripts are not executed.
• Content Security Policy (CSP): Implement CSP to restrict the sources of executable scripts.

10. Describe the role of a Security Operations Center (SOC).

A Security Operations Center (SOC) is a centralized unit that monitors, detects, and responds to cybersecurity incidents within an organization. It plays a crucial role in maintaining the security posture of the organization.

Roles and Responsibilities:

• Monitoring: Continuous monitoring of network traffic, systems, and applications for signs of suspicious activity.
• Incident Response: Detecting, analyzing, and responding to security incidents to mitigate their impact.
• Threat Intelligence: Gathering and analyzing threat intelligence to anticipate and prevent potential attacks.
• Vulnerability Management: Identifying and addressing vulnerabilities in the organization's infrastructure.
• Compliance: Ensuring compliance with security policies, regulations, and standards.
• Reporting: Providing regular reports and metrics on the organization's security posture and incident response activities.