Ethical Hacking Fundamentals

What is Ethical Hacking?

Ethical hacking, also known as penetration testing or white-hat hacking, is the practice of testing computer systems, networks, or applications to find security vulnerabilities that malicious hackers could exploit. Ethical hackers use the same techniques as malicious hackers but with permission and for the purpose of improving security.

Types of Hackers

• White Hat (Ethical Hackers): Authorized security professionals who test systems with permission
• Black Hat: Malicious hackers who break into systems illegally for personal gain
• Gray Hat: Hackers who operate between ethical and unethical boundaries
• Script Kiddies: Inexperienced individuals using pre-made tools without understanding
• Hacktivists: Hackers motivated by political or social causes

Phases of Ethical Hacking

1. Reconnaissance (Information Gathering)

Collecting information about the target system through:

• Passive reconnaissance (OSINT, social media, public records)
• Active reconnaissance (network scanning, port scanning)
• Social engineering techniques

2. Scanning

Identifying live hosts, open ports, and services:

• Network scanning (Nmap, Netcat)
• Vulnerability scanning (Nessus, OpenVAS)
• Service enumeration

3. Gaining Access

Exploiting vulnerabilities to gain unauthorized access:

• Password cracking
• Exploiting software vulnerabilities
• Social engineering attacks
• SQL injection, XSS, and other web attacks

4. Maintaining Access

Establishing persistent access to the compromised system:

• Installing backdoors
• Creating rootkits
• Privilege escalation

5. Covering Tracks

Hiding evidence of the intrusion:

• Clearing logs
• Hiding files
• Removing indicators of compromise

Common Attack Vectors

Network Attacks

• Man-in-the-Middle (MITM): Intercepting communication between two parties
• DDoS: Overwhelming a system with traffic
• Packet Sniffing: Capturing network traffic
• ARP Spoofing: Manipulating ARP tables

Web Application Attacks

• SQL Injection: Injecting malicious SQL code
• Cross-Site Scripting (XSS): Injecting malicious scripts
• CSRF: Forcing users to execute unwanted actions
• Directory Traversal: Accessing files outside web root

Social Engineering

• Phishing: Fraudulent emails to steal credentials
• Pretexting: Creating false scenarios to gain information
• Baiting: Offering something enticing to trick victims
• Tailgating: Following authorized personnel into secure areas

Essential Tools

Reconnaissance

• Nmap - Network scanning
• Maltego - OSINT and data mining
• theHarvester - Email and subdomain gathering

Exploitation

• Metasploit - Exploitation framework
• Burp Suite - Web application testing
• SQLmap - SQL injection tool

Password Cracking

• John the Ripper - Password cracker
• Hashcat - Advanced password recovery
• Hydra - Network login cracker

Legal and Ethical Considerations

• Always get written permission before testing any system
• Understand the scope of engagement and stay within bounds
• Follow the Computer Fraud and Abuse Act (CFAA) and local laws
• Maintain confidentiality of discovered vulnerabilities
• Report findings responsibly to the organization
• Never cause intentional damage to systems

Certifications

• CEH (Certified Ethical Hacker): Entry-level certification
• OSCP (Offensive Security Certified Professional): Hands-on penetration testing
• GPEN (GIAC Penetration Tester): Advanced penetration testing
• CISSP: Comprehensive information security certification

Best Practices

• Stay updated with the latest vulnerabilities and exploits
• Practice in legal environments (CTF challenges, HackTheBox, TryHackMe)
• Document all findings thoroughly
• Understand both offensive and defensive security
• Develop strong programming and scripting skills
• Join the security community and share knowledge