CEH Certified Ethical Hacker All-in-One Exam Guide

1. Essential Security and Network Knowledge

Those of you looking for exact test questions and rote memorization to pass the exam will not find it in this publication, nor any other.

Foundation of Knowledge. Ethical hacking requires a solid understanding of security principles and networking fundamentals. This includes familiarity with the OSI model, TCP/IP protocols, and common security terminology.

Security Basics. Key concepts include the CIA triad (Confidentiality, Integrity, Availability), risk management, and security policies. Understanding these elements is crucial for identifying vulnerabilities and implementing effective countermeasures. For example:

• Preventative measures like authentication
• Detective measures like audit logs
• Corrective measures like backups

Networking is Key. A strong grasp of TCP/IP networking is essential. This includes understanding subnetting, port numbers, and the three-way handshake. These concepts are foundational for understanding how attacks work and how to defend against them.

2. Mastering Reconnaissance Techniques

Passive reconnaissance involves gathering information about your target without their knowledge, whereas active reconnaissance uses tools and techniques that may or may not be discovered but put your activities as a hacker at more risk of discovery.

Information Gathering. Reconnaissance, or footprinting, is the initial phase of ethical hacking, involving gathering information about the target. This can be done passively or actively.

Passive Footprinting. Passive footprinting involves collecting publicly available information without directly interacting with the target. This includes:

• Using search engines
• Reviewing social media profiles
• Analyzing website data

Active Footprinting. Active footprinting involves direct interaction with the target, which carries a higher risk of detection. This includes:

• Social engineering
• Network sniffing
• Dumpster diving

3. Scanning and Enumeration Fundamentals

Scanning is the process of discovering systems on the network and taking a look at what open ports and applications may be running.

Identifying Targets. Scanning and enumeration build upon reconnaissance by actively probing the target network. This involves identifying live systems, open ports, and running services.

Scanning Techniques. Key techniques include:

• TCP connect scans
• SYN scans (half-open scans)
• UDP scans
• XMAS scans

Enumeration. Enumeration involves gathering detailed information about the target systems, such as user accounts, network shares, and software versions. This information is crucial for identifying potential vulnerabilities.

4. Sniffing and Evasion Tactics

Sniffing (also known as wiretapping by law enforcement types, something we’ll examine in detail later) is the art of capturing packets as they pass on a wire, or over the airwaves, to review for interesting information.

Packet Capture. Sniffing involves capturing network traffic to analyze data packets. This can be done passively or actively.

Active vs. Passive Sniffing. Passive sniffing involves capturing traffic without altering it, while active sniffing involves techniques like ARP poisoning to redirect traffic.

Evasion Techniques. To avoid detection, ethical hackers need to understand evasion techniques, such as:

• Packet fragmentation
• IP address spoofing
• Using proxies and anonymizers

5. System Hacking Methodologies

In the gaining access phase, true attacks are leveled against the targets enumerated in the second phase.

Gaining Access. System hacking involves exploiting vulnerabilities to gain unauthorized access to systems. This includes password cracking, privilege escalation, and executing applications.

Password Attacks. Password attacks can be online (directly against the system) or offline (against a stolen password database). Common techniques include:

• Dictionary attacks
• Brute-force attacks
• Hybrid attacks

Privilege Escalation. Once initial access is gained, privilege escalation involves exploiting system misconfigurations or vulnerabilities to gain higher-level access, such as administrator or root privileges.

6. Web-Based Hacking Strategies

Web servers are unique entities in the virtual world we play in.

Web Server Architecture. Web servers are prime targets for attackers due to their public-facing nature. Understanding web server architecture, including common web server software (Apache, IIS, Nginx), is crucial for identifying vulnerabilities.

Web Application Attacks. Web application attacks target vulnerabilities in web applications, such as:

• SQL injection
• Cross-site scripting (XSS)
• Cross-site request forgery (CSRF)

Countermeasures. Countermeasures include secure coding practices, input validation, and regular security assessments.

7. Wireless Network Intrusion Techniques

If data is sent over the airwaves, it can be received over the airwaves—by anyone (maybe not in clear text, and maybe not easily discernable, but it can be received).

Wireless Security. Wireless networks are vulnerable to various attacks due to their open nature. Understanding wireless standards (802.11), encryption protocols (WEP, WPA, WPA2), and authentication methods is essential for securing wireless networks.

Wireless Hacking Techniques. Common techniques include:

• War driving
• Rogue access points
• MAC address spoofing
• WEP/WPA cracking

Mobile Attacks. Mobile devices are increasingly targeted by attackers. Common mobile attacks include:

• SMS phishing (smishing)
• Malicious apps
• Bluetooth attacks

8. Cloud Computing Security Essentials

Cloud computing provides user and enterprise subscribers on-demand delivery of various IT services as a metered service over a network.

Cloud Computing Models. Cloud computing offers various service models, including:

• Infrastructure as a Service (IaaS)
• Platform as a Service (PaaS)
• Software as a Service (SaaS)

Cloud Deployment Models. Cloud services can be deployed in various models, including:

• Public cloud
• Private cloud
• Community cloud
• Hybrid cloud

Cloud Security Threats. Common cloud security threats include data breaches, abuse of cloud resources, insecure interfaces and APIs, and insufficient due diligence.

9. Trojans and Other Attacks

A Trojan is software that appears to perform a desirable function for the user prior to running or installing it but instead performs a function, usually without the user’s knowledge, that steals information or otherwise harms the system (or data).

Malware Types. Malware includes various types of malicious software, such as:

• Trojans
• Viruses
• Worms
• Ransomware

DoS Attacks. Denial-of-service (DoS) attacks aim to disrupt the availability of systems or services. Common DoS techniques include:

• SYN floods
• ICMP floods
• Application-level attacks

10. Cryptography 101

Cryptography is the science or study of protecting information, whether in transit or at rest, by using techniques to render the information unusable to anyone who does not possess the means to decrypt it.

Encryption Algorithms. Cryptography involves using encryption algorithms to protect data. These algorithms can be symmetric (using a single key for encryption and decryption) or asymmetric (using a key pair).

Symmetric Algorithms. Examples include:

• DES
• 3DES
• AES

Asymmetric Algorithms. Examples include:

• RSA
• Diffie-Hellman
• ECC

Hashing Algorithms. Hashing algorithms are one-way functions used to ensure data integrity. Examples include MD5, SHA-1, and SHA-2.

11. Low Tech: Social Engineering and Physical Security

Social engineering is the art of manipulating a person, or a group of people, into providing information or a service they otherwise would never have given.

Human Manipulation. Social engineering involves manipulating individuals to gain access to information or systems. This can be done through various techniques, such as:

• Impersonation
• Phishing
• Pretexting

Physical Security. Physical security involves protecting physical assets from unauthorized access or damage. This includes measures such as:

• Locks and alarms
• Biometric scanners
• Security guards

Social Engineering Tactics. Common social engineering tactics include:

• Dumpster diving
• Shoulder surfing
• Reverse social engineering

12. The Pen Test: Putting It All Together

Pen testers are thorough in their work for the customer. Hackers just discover what is necessary to accomplish their goal.

Comprehensive Testing. A penetration test (pen test) is a comprehensive assessment of an organization's security posture. It involves simulating real-world attacks to identify vulnerabilities and weaknesses.

Pen Test Phases. The pen test process typically involves three phases:

• Pre-attack (reconnaissance and planning)
• Attack (exploitation and gaining access)
• Post-attack (cleanup and reporting)

Pen Test Deliverables. The final deliverable of a pen test is a comprehensive report that includes:

• Executive summary
• List of findings
• Analysis of vulnerabilities
• Recommended mitigation steps

Last updated: February 23, 2025