Ethical Hacking Foundations

Overview

This lecture covers the foundations of practical ethical hacking, including the structure of penetration tests, essential networking and Linux concepts, Python scripting, and strategies for effective note-taking and passive reconnaissance.

Introduction to Ethical Hacking & Penetration Testing

• Ethical hacking involves simulating cyberattacks to identify vulnerabilities in organizations before malicious actors do.
• Penetration testing types include external, internal, web application, wireless, physical, and red/purple team engagements.
• External pen tests mimic attacks from outside the organization and focus on OSINT; internal tests simulate inside attacks with emphasis on Active Directory.
• Each assessment includes report writing and debriefing, requiring both technical and communication skills.
• Effective note-taking is essential for both learning and performing assessments.

Note-Keeping for Cybersecurity

• Use structured, modular notes including screenshots and commands for future reference.
• Suggested apps: KeepNote, CherryTree, OneNote, Joplin; screenshot tools: Greenshot or Flameshot.
• Mark off findings as they are added to reports for organization.

Networking Refresher

• IP addresses: IPv4 (32-bit decimal, common), IPv6 (128-bit hex, rare), NAT enables multiple devices on one public IP.
• Private IP address ranges: Class A (10.x.x.x), Class B (172.16.x.x–172.31.x.x), Class C (192.168.x.x).
• MAC addresses identify network interface hardware at Layer 2 (Switching).
• TCP (reliable, connection-oriented, uses three-way handshake) vs UDP (fast, connectionless).
• OSI Model: Physical, Data Link, Network, Transport, Session, Presentation, Application.
• Subnetting defines network size; slash notation (e.g., /24) indicates hosts—common networks use 255.255.255.0.

Virtual Machines & Kali Linux Setup

• Use VMware (Windows/Linux) or VirtualBox (Mac/Linux) to run virtual labs.
• Install Kali Linux (Debian-based) as the main penetration testing environment.

Basic Linux Skills for Hackers

• Familiarity with command line: navigation (cd, ls, pwd), making/removing files and folders (mkdir, rm), hidden files with ls -la.
• Sudo grants temporary root (admin) privileges.
• File permissions: rwx (read, write, execute), chmod and numeric codes (e.g., 777 = full access).
• Basic networking commands: ifconfig/ipa, iwconfig, ping, arp, route, netstat.
• Installing/updating tools: apt update & upgrade, git clone, running scripts.
• Starting/stopping services: systemctl, use python to serve files quickly.

Python Fundamentals for Hacking

• Focus on code reading and basic scripting: strings, math, variables, functions, lists, tuples, dictionaries, loops, and classes.
• Input/output handling, file read/write, working with modules, socket programming.
• Projects: build a basic port scanner and a budget calculator app.
• Emphasize understanding script flow, logic, and error handling.

Five Stages of Ethical Hacking

• Reconnaissance (passive/active), Scanning/Enumeration, Gaining Access (Exploitation), Maintaining Access, Covering Tracks/Reporting.
• Course structure follows this hacker workflow for hands-on learning.

Passive Information Gathering (Recon)

• Target validation is crucial; always confirm engagement scope.
• Use OSINT for employee emails, job info, badge photos, and physical layouts.
• Tools/websites: Hunter.io, phonebook.cz, Clearbit, forgot password recovery, email checkers.
• Data breach analysis: search for exposed credentials using breach compilation datasets or services like Dhash, hashes.org.
• Methodology: correlate user emails, usernames, passwords, hashes, and associated accounts for pivoting and attacks.

Key Terms & Definitions

• Penetration Test — Simulated cyberattack to assess security.
• OSINT (Open Source Intelligence) — Collecting public data for reconnaissance.
• NAT (Network Address Translation) — Allows multiple devices to share a public IP.
• TCP/UDP — Network protocols for data transmission; TCP is reliable, UDP is fast.
• OSI Model — Framework dividing network functions into seven layers.
• Subnetting — Dividing networks for organization and access control.
• Sudo — Command to run Linux operations with elevated privileges.
• rwX — File permissions: Read, Write, Execute.
• Reconnaissance — The first phase in ethical hacking to gather information.

Action Items / Next Steps

• Install Kali Linux on your VM environment of choice.
• Set up your preferred note-taking and screenshot tools.
• Complete networking and Linux command practice as covered.
• Review your notes, especially on subnetting and the OSI model.
• Begin passive reconnaissance on a chosen legal target (e.g., a bug bounty program).
• Proceed to Part 2 via the provided link when ready.