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Linux Fundamentals

This module covers the fundamentals required to work comfortably with the Linux operating system and shell.

4.62

Created by Cry0l1t3
Co-Authors: knightmare

Fundamental General

Summary

Linux is an indispensable tool and system in the field of cybersecurity. Many servers run on Linux and offer a wide range of possibilities for offensive security practitioners, network defenders, and systems administrators. This module covers the essentials for starting with the Linux operating system and terminal.

In this module, we will cover:

  • Linux structure
  • Using the shell
  • Navigating the Linux operating system
  • Working with files and directories
  • Linux administration
  • Service management
  • Permissions management

CREST CPSA/CRT-related Sections:

  • All sections

CREST CCT APP-related Sections:

  • All sections

This module is broken down into sections with accompanying hands-on exercises to practice each of the tactics and techniques we cover. The module ends with a practical hands-on skills assessment to gauge your understanding of the various topic areas.

As you work through the module, you will see example commands and command output for the various topics introduced. It is worth reproducing as many of these examples as possible to reinforce further the concepts introduced in each section. You can do this in the Pwnbox provided in the interactive sections or your own virtual machine.

You can start and stop the module at any time and pick up where you left off. There is no time limit or "grading," but you must complete all of the exercises and the skills assessment to receive the maximum number of cubes and have this module marked as complete in any paths you have chosen.

The module is classified as "Fundamental." It assumes that the user has little to no prior experience with the Linux operating system but is generally comfortable navigating a graphical operating system such as Windows.

This module has no prerequisites but serves as the basis for many of the modules contained within the Academy. Completion and an in-depth understanding of this module are crucial for success as you progress through the Academy and Hack the Box platforms.

Linux Structure


History

Many events led up to creating the first Linux kernel and, ultimately, the Linux operating system (OS), starting with the Unix operating system's release by Ken Thompson and Dennis Ritchie (whom both worked for AT&T at the time) in 1970. The Berkeley Software Distribution (BSD) was released in 1977, but since it contained the Unix code owned by AT&T, a resulting lawsuit limited the development of BSD. Richard Stallman started the GNU project in 1983. His goal was to create a free Unix-like operating system, and part of his work resulted in the GNU General Public License (GPL) being created. Projects by others over the years failed to result in a working, free kernel that would become widely adopted until the creation of the Linux kernel.

At first, Linux was a personal project started in 1991 by a Finnish student named Linus Torvalds. His goal was to create a new, free operating system kernel. Over the years, the Linux kernel has gone from a small number of files written in C under licensing that prohibited commercial distribution to the latest version with over 23 million source code lines (comments excluded), licensed under the GNU General Public License v2.

Linux is available in over 600 distributions (or an operating system based on the Linux kernel and supporting software and libraries). Some of the most popular and well-known being Ubuntu, Debian, Fedora, OpenSUSE, elementary, Manjaro, Gentoo Linux, RedHat, and Linux Mint.

Linux is generally considered more secure than other operating systems, and while it has had many kernel vulnerabilities in the past, it is becoming less and less frequent. It is less susceptible to malware than Windows operating systems and is very frequently updated. Linux is also very stable and generally affords very high performance to the end-user. However, it can be more difficult for beginners and does not have as many hardware drivers as Windows.

Since Linux is free and open-source, the source code can be modified and distributed commercially or non-commercially by anyone. Linux-based operating systems run on servers, mainframes, desktops, embedded systems such as routers, televisions, video game consoles, and more. The overall Android operating system that runs on smartphones and tablets is based on the Linux kernel, and because of this, Linux is the most widely installed operating system.

Linux is an operating system like Windows, iOS, Android, or macOS. An OS is software that manages all of the hardware resources associated with our computer. That means that an OS manages the whole communication between software and hardware. Also, there exist many different distributions (distro). It is like a version of Windows operating systems.

With the interactive instances, we get access to the Pwnbox, a customized version of Parrot OS. This will be the primary OS we will work with through the modules. Parrot OS is a Debian-based Linux distribution that focuses on security, privacy, and development.


Philosophy

Linux follows five core principles:

Principle Description
Everything is a file All configuration files for the various services running on the Linux operating system are stored in one or more text files.
Small, single-purpose programs Linux offers many different tools that we will work with, which can be combined to work together.
Ability to chain programs together to perform complex tasks The integration and combination of different tools enable us to carry out many large and complex tasks, such as processing or filtering specific data results.
Avoid captive user interfaces Linux is designed to work mainly with the shell (or terminal), which gives the user greater control over the operating system.
Configuration data stored in a text file An example of such a file is the /etc/passwd file, which stores all users registered on the system.

Components

Component Description
Bootloader A piece of code that runs to guide the booting process to start the operating system. Parrot Linux uses the GRUB Bootloader.
OS Kernel The kernel is the main component of an operating system. It manages the resources for system's I/O devices at the hardware level.
Daemons Background services are called "daemons" in Linux. Their purpose is to ensure that key functions such as scheduling, printing, and multimedia are working correctly. These small programs load after we booted or log into the computer.
OS Shell The operating system shell or the command language interpreter (also known as the command line) is the interface between the OS and the user. This interface allows the user to tell the OS what to do. The most commonly used shells are Bash, Tcsh/Csh, Ksh, Zsh, and Fish.
Graphics server This provides a graphical sub-system (server) called "X" or "X-server" that allows graphical programs to run locally or remotely on the X-windowing system.
Window Manager Also known as a graphical user interface (GUI). There are many options, including GNOME, KDE, MATE, Unity, and Cinnamon. A desktop environment usually has several applications, including file and web browsers. These allow the user to access and manage the essential and frequently accessed features and services of an operating system.
Utilities Applications or utilities are programs that perform particular functions for the user or another program.

Linux Architecture

The Linux operating system can be broken down into layers:

Layer Description
Hardware Peripheral devices such as the system's RAM, hard drive, CPU, and others.
Kernel The core of the Linux operating system whose function is to virtualize and control common computer hardware resources like CPU, allocated memory, accessed data, and others. The kernel gives each process its own virtual resources and prevents/mitigates conflicts between different processes.
Shell A command-line interface (CLI), also known as a shell that a user can enter commands into to execute the kernel's functions.
System Utility Makes available to the user all of the operating system's functionality.

File System Hierarchy

The Linux operating system is structured in a tree-like hierarchy and is documented in the Filesystem Hierarchy Standard (FHS). Linux is structured with the following standard top-level directories:

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Path Description
/ The top-level directory is the root filesystem and contains all of the files required to boot the operating system before other filesystems are mounted as well as the files required to boot the other filesystems. After boot, all of the other filesystems are mounted at standard mount points as subdirectories of the root.
/bin Contains essential command binaries.
/boot Consists of the static bootloader, kernel executable, and files required to boot the Linux OS.
/dev Contains device files to facilitate access to every hardware device attached to the system.
/etc Local system configuration files. Configuration files for installed applications may be saved here as well.
/home Each user on the system has a subdirectory here for storage.
/lib Shared library files that are required for system boot.
/media External removable media devices such as USB drives are mounted here.
/mnt Temporary mount point for regular filesystems.
/opt Optional files such as third-party tools can be saved here.
/root The home directory for the root user.
/sbin This directory contains executables used for system administration (binary system files).
/tmp The operating system and many programs use this directory to store temporary files. This directory is generally cleared upon system boot and may be deleted at other times without any warning.
/usr Contains executables, libraries, man files, etc.
/var This directory contains variable data files such as log files, email in-boxes, web application related files, cron files, and more.

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Relevant Paths

This module progresses you towards the following Paths

Operating System Fundamentals

To succeed in information security, we must have a deep understanding of the Windows and Linux operating systems and be comfortable navigating the command line on both as a "power user." Much of our time in any role, but especially penetration testing, is spent in a Linux shell, Windows cmd or PowerShell console, so we must have the skills to navigate both types of operating systems with ease, manage system services, install applications, manage permissions, and harden the systems we work from in accordance with security best practices.

Easy Path Sections 44 Sections
Required: 20
Reward: +20
Path Modules
Linux Fundamentals
Fundamental
Path Sections 30 Sections
Reward: +10 UPDATED
This module covers the fundamentals required to work comfortably with the Linux operating system and shell.
Windows Fundamentals
Fundamental
Path Sections 14 Sections
Reward: +10
This module covers the fundamentals required to work comfortably with the Windows operating system.

CREST CPSA/CRT Preparation

This is a skill path to prepare you for CREST's CPSA and CRT exams. The following CPSA/CRT syllabus areas (IDs) are covered: A1, A2, A3, A4, A5, B1, B4, B5, B6, B8, B9, B13, B14, C1, C2, C3, C4, D1, D2, E1, E2, E3, E4, E5, E9, F1, F2, F3, F4, F5, F6, F7, F8, F9, G1, G2, G4, G5, G6, G7, G8, G9, H1, H2, H3, H4, H5, H6, H8, H9, H10, H11, H12, H13, I1, I2, I3, I6, J1, J2, J3. Take your time to complete all related sections and when you are ready you can book your CREST exam through the following links. CREST CPSA: https://www.crest-approved.org/certification-careers/crest-certifications/crest-practitioner-security-analyst/. CREST CRT: https://www.crest-approved.org/certification-careers/crest-certifications/crest-registered-penetration-tester/.

Medium Path Sections 658 Sections
Required: 2980
Reward: +700
Path Modules
Introduction to Networking
Fundamental
Path Sections 21 Sections
Reward: +10 UPDATED
As an information security professional, a firm grasp of networking fundamentals and the required components is necessary. Without a strong foundation in networking, it will be tough to progress in any area of information security. Understanding how a network is structured and how the communication between the individual hosts and servers takes place using the various protocols allows us to understand the entire network structure and its network traffic in detail and how different communication standards are handled. This knowledge is essential to create our tools and to interact with the protocols.
Web Requests
Fundamental
Path Sections 8 Sections
Reward: +10
This module introduces the topic of HTTP web requests and how different web applications utilize them to communicate with their backends.
Introduction to Web Applications
Fundamental
Path Sections 17 Sections
Reward: +10
In the Introduction to Web Applications module, you will learn all of the basics of how web applications work and begin to look at them from an information security perspective.
Linux Fundamentals
Fundamental
Path Sections 30 Sections
Reward: +10 UPDATED
This module covers the fundamentals required to work comfortably with the Linux operating system and shell.
Windows Fundamentals
Fundamental
Path Sections 14 Sections
Reward: +10
This module covers the fundamentals required to work comfortably with the Windows operating system.
Introduction to Windows Command Line
Easy
Path Sections 23 Sections
Reward: +10
As administrators and Pentesters, we may not always be able to utilize a graphical user interface for the actions we need to perform. Introduction to Windows Command Line aims to introduce students to the wide range of uses for Command Prompt and PowerShell within a Windows environment. We will cover basic usage of both key executables for administration, useful PowerShell cmdlets and modules, and different ways to leverage these tools to our benefit.
Intro to Network Traffic Analysis
Medium
Path Sections 15 Sections
Reward: +10
Network traffic analysis is used by security teams to monitor network activity and look for anomalies that could indicate security and operational issues. Offensive security practitioners can use network traffic analysis to search for sensitive data such as credentials, hidden applications, reachable network segments, or other potentially sensitive information "on the wire." Network traffic analysis has many uses for attackers and defenders alike.
Penetration Testing Process
Fundamental
Path Sections 15 Sections
Reward: +10 UPDATED
This module teaches the penetration testing process broken down into each stage and discussed in detail. We will cover many aspects of the role of a penetration tester during a penetration test, explained and illustrated with detailed examples. The module also covers pre-engagement steps like the criteria for establishing a contract with a client for a penetration testing engagement.
Network Enumeration with Nmap
Easy
Path Sections 12 Sections
Reward: +10
Nmap is one of the most used networking mapping and discovery tools because of its accurate results and efficiency. The tool is widely used by both offensive and defensive security practitioners. This module covers fundamentals that will be needed to use the Nmap tool for performing effective network enumeration.
Footprinting
Medium
Path Sections 21 Sections
Reward: +20 UPDATED
This module covers techniques for footprinting the most commonly used services in almost all enterprise and business IT infrastructures. Footprinting is an essential phase of any penetration test or security audit to identify and prevent information disclosure. Using this process, we examine the individual services and attempt to obtain as much information from them as possible.
Information Gathering - Web Edition
Easy
Path Sections 10 Sections
Reward: +20
This module covers techniques for identifying and analyzing an organization's web application-based attack surface and tech stack. Information gathering is an essential part of any web application penetration test, and it can be performed either passively or actively.
Vulnerability Assessment
Easy
Path Sections 17 Sections
Reward: +10
This module introduces the concept of Vulnerability Assessments. We will review the differences between vulnerability assessments and penetration tests, how to carry out a vulnerability assessment, how to interpret the assessment results, and how to deliver an effective vulnerability assessment report.
File Transfers
Medium
Path Sections 10 Sections
Reward: +10
During an assessment, it is very common for us to transfer files to and from a target system. This module covers file transfer techniques leveraging tools commonly available across all versions of Windows and Linux systems.
Shells & Payloads
Medium
Path Sections 17 Sections
Reward: +10
Gain the knowledge and skills to identify and use shells & payloads to establish a foothold on vulnerable Windows & Linux systems. This module utilizes a fictitious scenario where the learner will place themselves in the perspective of a sysadmin trying out for a position on CAT5 Security's network penetration testing team.
Using the Metasploit Framework
Easy
Path Sections 15 Sections
Reward: +10
The Metasploit Framework is an open-source set of tools used for network enumeration, attacks, testing security vulnerabilities, evading detection, performing privilege escalation attacks, and performing post-exploitation.
Password Attacks
Medium
Path Sections 22 Sections
Reward: +10 UPDATED
Passwords are still the primary method of authentication in corporate networks. If strong password policies are not in place, users will often opt for weak, easy-to-remember passwords that can often be cracked offline and used to further our access. We will encounter passwords in many forms during our assessments. We must understand the various ways they are stored, how they can be retrieved, methods to crack weak passwords, ways to use hashes that cannot be cracked, and hunting for weak/default password usage.
Attacking Common Services
Medium
Path Sections 19 Sections
Reward: +20
Organizations regularly use a standard set of services for different purposes. It is vital to conduct penetration testing activities on each service internally and externally to ensure that they are not introducing security threats. This module will cover how to enumerate each service and test it against known vulnerabilities and exploits with a standard set of tools.
Cracking Passwords with Hashcat
Medium
Path Sections 14 Sections
Reward: +20
This module covers the fundamentals of password cracking using the Hashcat tool.
Introduction to Active Directory
Fundamental
Path Sections 16 Sections
Reward: +10
Active Directory (AD) is present in the majority of corporate environments. Due to its many features and complexity, it presents a vast attack surface. To be successful as penetration testers and information security professionals, we must have a firm understanding of Active Directory fundamentals, AD structures, functionality, common AD flaws, misconfigurations, and defensive measures.
Pivoting, Tunneling, and Port Forwarding
Medium
Path Sections 18 Sections
Reward: +20
Once a foothold is gained during an assessment, it may be in scope to move laterally and vertically within a target network. Using one compromised machine to access another is called pivoting and allows us to access networks and resources that are not directly accessible to us through the compromised host. Port forwarding accepts the traffic on a given IP address and port and redirects it to a different IP address and port combination. Tunneling is a technique that allows us to encapsulate traffic within another protocol so that it looks like a benign traffic stream.
Active Directory Enumeration & Attacks
Medium
Path Sections 36 Sections
Reward: +20
Active Directory (AD) is the leading enterprise domain management suite, providing identity and access management, centralized domain administration, authentication, and much more. Due to the many features and complexity of AD, it presents a large attack surface that is difficult to secure properly. To be successful as infosec professionals, we must understand AD architectures and how to secure our enterprise environments. As Penetration testers, having a firm grasp of what tools, techniques, and procedures are available to us for enumerating and attacking AD environments and commonly seen AD misconfigurations is a must.
Linux Privilege Escalation
Easy
Path Sections 15 Sections
Reward: +20
Privilege escalation is a crucial phase during any security assessment. During this phase, we attempt to gain access to additional users, hosts, and resources to move closer to the assessment's overall goal. There are many ways to escalate privileges. This module aims to cover the most common methods emphasizing real-world misconfigurations and flaws that we may encounter in a client environment. The techniques covered in this module are not an exhaustive list of all possibilities and aim to avoid extreme "edge-case" tactics that may be seen in a Capture the Flag (CTF) exercise.
Windows Privilege Escalation
Medium
Path Sections 31 Sections
Reward: +20 UPDATED
After gaining a foothold, elevating our privileges will provide more options for persistence and may reveal information stored locally that can further our access in the environment. Enumeration is the key to privilege escalation. When you gain initial shell access to the host, it is important to gain situational awareness and uncover details relating to the OS version, patch level, any installed software, our current privileges, group memberships, and more. Windows presents an enormous attack surface and, being that most companies run Windows hosts in some way, we will more often than not find ourselves gaining access to Windows machines during our assessments. This covers common methods while emphasizing real-world misconfigurations and flaws that we may encounter during an assessment. There are many additional "edge-case" possibilities not covered in this module. We will cover both modern and legacy Windows Server and Desktop versions that may be present in a client environment.
Using Web Proxies
Easy
Path Sections 15 Sections
Reward: +20
Web application penetration testing frameworks are an essential part of any web penetration test. This module will teach you two of the best frameworks: Burp Suite and OWASP ZAP.
Attacking Web Applications with Ffuf
Easy
Path Sections 13 Sections
Reward: +10
This module covers the fundamental enumeration skills of web fuzzing and directory brute forcing using the Ffuf tool. The techniques learned in this module will help us in locating hidden pages, directories, and parameters when targeting web applications.
Login Brute Forcing
Easy
Path Sections 11 Sections
Reward: +20
Learn how to brute force logins for various types of services and create custom wordlists based on your target.
HTTPs/TLS Attacks
Medium
Path Sections 15 Sections
Reward: +100
This module covers details on Transport Layer Security (TLS) and how it helps to make HTTP secure with the widely used HTTPS. That includes how TLS works, how TLS sessions are established, common TLS misconfigurations, as well as famous attacks on TLS. We will discuss how to identify, exploit, and prevent TLS attacks.
Cross-Site Scripting (XSS)
Easy
Path Sections 10 Sections
Reward: +20
Cross-Site Scripting (XSS) vulnerabilities are among the most common web application vulnerabilities. An XSS vulnerability may allow an attacker to execute arbitrary JavaScript code within the target's browser and result in complete web application compromise if chained together with other vulnerabilities. This module will teach you how to identify XSS vulnerabilities and exploit them.
Session Security
Medium
Path Sections 14 Sections
Reward: +20
Maintaining and keeping track of a user's session is an integral part of web applications. It is an area that requires extensive testing to ensure it is set up robustly and securely. This module covers the most common attacks and vulnerabilities that can affect web application sessions, such as Session Hijacking, Session Fixation, Cross-Site Request Forgery, Cross-Site Scripting, and Open Redirects.
SQL Injection Fundamentals
Medium
Path Sections 17 Sections
Reward: +10
Databases are an important part of web application infrastructure and SQL (Structured Query Language) to store, retrieve, and manipulate information stored in them. SQL injection is a code injection technique used to take advantage of coding vulnerabilities and inject SQL queries via an application to bypass authentication, retrieve data from the back-end database, or achieve code execution on the underlying server.
SQLMap Essentials
Easy
Path Sections 11 Sections
Reward: +20
The SQLMap Essentials module will teach you the basics of using SQLMap to discover various types of SQL Injection vulnerabilities, all the way to the advanced enumeration of databases to retrieve all data of interest.
File Inclusion
Medium
Path Sections 11 Sections
Reward: +10
File Inclusion is a common web application vulnerability, which can be easily overlooked as part of a web application's functionality.
File Upload Attacks
Medium
Path Sections 11 Sections
Reward: +20
Arbitrary file uploads are among the most critical web vulnerabilities. These flaws enable attackers to upload malicious files, execute arbitrary commands on the back-end server, and even take control over the entire server and all web applications hosted on it and potentially gain access to sensitive data or cause a service disruption.
Command Injections
Medium
Path Sections 12 Sections
Reward: +20
Command injection vulnerabilities can be leveraged to compromise a hosting server and its entire network. This module will teach you how to identify and exploit command injection vulnerabilities and how to use various filter bypassing techniques to avoid security mitigations.
Broken Authentication
Medium
Path Sections 14 Sections
Reward: +20
Authentication is probably the most straightforward and prevalent measure used to secure access to resources, and it's the first line of defense against unauthorized access. Broken authentication is currently listed as #7 on the 2021 OWASP Top 10 Web Application Security Risks, falling under the broader category of Identification and Authentication failures. A vulnerability or misconfiguration at the authentication stage can devastatingly impact an application's overall security.
Web Attacks
Medium
Path Sections 18 Sections
Reward: +20
This module covers three common web vulnerabilities, HTTP Verb Tampering, IDOR, and XXE, each of which can have a significant impact on a company's systems. We will cover how to identify, exploit, and prevent each of them through various methods.
Attacking Common Applications
Medium
Path Sections 33 Sections
Reward: +20 UPDATED
Penetration Testers can come across various applications, such as Content Management Systems, custom web applications, internal portals used by developers and sysadmins, and more. It's common to find the same applications across many different environments. While an application may not be vulnerable in one environment, it may be misconfigured or unpatched in the next. It is important as an assessor to have a firm grasp of enumerating and attacking the common applications discussed in this module. This knowledge will help when encountering other types of applications during assessments.
Web Service & API Attacks
Medium
Path Sections 13 Sections
Reward: +20
Web services and APIs are frequently exposed to provide certain functionalities in a programmatic way between heterogeneous devices and software components. Both web services and APIs can assist in integrating different applications or facilitate separation within a given application. This module covers how to identify the functionality a web service or API offers and exploit any security-related inefficiencies.
Hacking WordPress
Easy
Path Sections 16 Sections
Reward: +20
WordPress is an open-source Content Management System (CMS) that can be used for multiple purposes.
Documentation & Reporting
Easy
Path Sections 8 Sections
Reward: +20
Proper documentation is paramount during any engagement. The end goal of a technical assessment is the report deliverable which will often be presented to a broad audience within the target organization. We must take detailed notes and be very organized in our documentation, which will help us in the event of an incident during the assessment. This will also help ensure that our reports contain enough detail to illustrate the impact of our findings properly.

CREST CCT APP Preparation

This is a skill path to prepare you for CREST's CCT APP exam. The following CCT APP syllabus areas (IDs) are covered: A1, A2, A3, A4, A5, B1, B4, B5, B6, B8, B9, B13, B14, C1, C2, C3, C4, D1, D2, E1, E2, E3, E4, E5, E9, F1, F2, F3, F4, F5, F6, F7, F8, F9, G1, G2, G4, G5, G6, G7, G8, G9, H1, H2, H3, H4, H5, H6, H7, H8, H9, H10, H11, H12, H13, I1, I2, I3, I4, I5, I6, I7, I8, I9, I10, I11, I12, J1, J2, J3. Take your time to complete all related sections and when you are ready you can book your CREST exam through the following link. https://www.crest-approved.org/certification-careers/crest-certifications/crest-certified-web-application-tester/

Medium Path Sections 724 Sections
Required: 4980
Reward: +1100
Path Modules
Introduction to Networking
Fundamental
Path Sections 21 Sections
Reward: +10 UPDATED
As an information security professional, a firm grasp of networking fundamentals and the required components is necessary. Without a strong foundation in networking, it will be tough to progress in any area of information security. Understanding how a network is structured and how the communication between the individual hosts and servers takes place using the various protocols allows us to understand the entire network structure and its network traffic in detail and how different communication standards are handled. This knowledge is essential to create our tools and to interact with the protocols.
Web Requests
Fundamental
Path Sections 8 Sections
Reward: +10
This module introduces the topic of HTTP web requests and how different web applications utilize them to communicate with their backends.
Introduction to Web Applications
Fundamental
Path Sections 17 Sections
Reward: +10
In the Introduction to Web Applications module, you will learn all of the basics of how web applications work and begin to look at them from an information security perspective.
Linux Fundamentals
Fundamental
Path Sections 30 Sections
Reward: +10 UPDATED
This module covers the fundamentals required to work comfortably with the Linux operating system and shell.
Windows Fundamentals
Fundamental
Path Sections 14 Sections
Reward: +10
This module covers the fundamentals required to work comfortably with the Windows operating system.
Introduction to Windows Command Line
Easy
Path Sections 23 Sections
Reward: +10
As administrators and Pentesters, we may not always be able to utilize a graphical user interface for the actions we need to perform. Introduction to Windows Command Line aims to introduce students to the wide range of uses for Command Prompt and PowerShell within a Windows environment. We will cover basic usage of both key executables for administration, useful PowerShell cmdlets and modules, and different ways to leverage these tools to our benefit.
Intro to Network Traffic Analysis
Medium
Path Sections 15 Sections
Reward: +10
Network traffic analysis is used by security teams to monitor network activity and look for anomalies that could indicate security and operational issues. Offensive security practitioners can use network traffic analysis to search for sensitive data such as credentials, hidden applications, reachable network segments, or other potentially sensitive information "on the wire." Network traffic analysis has many uses for attackers and defenders alike.
Penetration Testing Process
Fundamental
Path Sections 15 Sections
Reward: +10 UPDATED
This module teaches the penetration testing process broken down into each stage and discussed in detail. We will cover many aspects of the role of a penetration tester during a penetration test, explained and illustrated with detailed examples. The module also covers pre-engagement steps like the criteria for establishing a contract with a client for a penetration testing engagement.
Network Enumeration with Nmap
Easy
Path Sections 12 Sections
Reward: +10
Nmap is one of the most used networking mapping and discovery tools because of its accurate results and efficiency. The tool is widely used by both offensive and defensive security practitioners. This module covers fundamentals that will be needed to use the Nmap tool for performing effective network enumeration.
Footprinting
Medium
Path Sections 21 Sections
Reward: +20 UPDATED
This module covers techniques for footprinting the most commonly used services in almost all enterprise and business IT infrastructures. Footprinting is an essential phase of any penetration test or security audit to identify and prevent information disclosure. Using this process, we examine the individual services and attempt to obtain as much information from them as possible.
Information Gathering - Web Edition
Easy
Path Sections 10 Sections
Reward: +20
This module covers techniques for identifying and analyzing an organization's web application-based attack surface and tech stack. Information gathering is an essential part of any web application penetration test, and it can be performed either passively or actively.
Vulnerability Assessment
Easy
Path Sections 17 Sections
Reward: +10
This module introduces the concept of Vulnerability Assessments. We will review the differences between vulnerability assessments and penetration tests, how to carry out a vulnerability assessment, how to interpret the assessment results, and how to deliver an effective vulnerability assessment report.
File Transfers
Medium
Path Sections 10 Sections
Reward: +10
During an assessment, it is very common for us to transfer files to and from a target system. This module covers file transfer techniques leveraging tools commonly available across all versions of Windows and Linux systems.
Shells & Payloads
Medium
Path Sections 17 Sections
Reward: +10
Gain the knowledge and skills to identify and use shells & payloads to establish a foothold on vulnerable Windows & Linux systems. This module utilizes a fictitious scenario where the learner will place themselves in the perspective of a sysadmin trying out for a position on CAT5 Security's network penetration testing team.
Using the Metasploit Framework
Easy
Path Sections 15 Sections
Reward: +10
The Metasploit Framework is an open-source set of tools used for network enumeration, attacks, testing security vulnerabilities, evading detection, performing privilege escalation attacks, and performing post-exploitation.
Password Attacks
Medium
Path Sections 22 Sections
Reward: +10 UPDATED
Passwords are still the primary method of authentication in corporate networks. If strong password policies are not in place, users will often opt for weak, easy-to-remember passwords that can often be cracked offline and used to further our access. We will encounter passwords in many forms during our assessments. We must understand the various ways they are stored, how they can be retrieved, methods to crack weak passwords, ways to use hashes that cannot be cracked, and hunting for weak/default password usage.
Attacking Common Services
Medium
Path Sections 19 Sections
Reward: +20
Organizations regularly use a standard set of services for different purposes. It is vital to conduct penetration testing activities on each service internally and externally to ensure that they are not introducing security threats. This module will cover how to enumerate each service and test it against known vulnerabilities and exploits with a standard set of tools.
Cracking Passwords with Hashcat
Medium
Path Sections 14 Sections
Reward: +20
This module covers the fundamentals of password cracking using the Hashcat tool.
Introduction to Active Directory
Fundamental
Path Sections 16 Sections
Reward: +10
Active Directory (AD) is present in the majority of corporate environments. Due to its many features and complexity, it presents a vast attack surface. To be successful as penetration testers and information security professionals, we must have a firm understanding of Active Directory fundamentals, AD structures, functionality, common AD flaws, misconfigurations, and defensive measures.
Pivoting, Tunneling, and Port Forwarding
Medium
Path Sections 18 Sections
Reward: +20
Once a foothold is gained during an assessment, it may be in scope to move laterally and vertically within a target network. Using one compromised machine to access another is called pivoting and allows us to access networks and resources that are not directly accessible to us through the compromised host. Port forwarding accepts the traffic on a given IP address and port and redirects it to a different IP address and port combination. Tunneling is a technique that allows us to encapsulate traffic within another protocol so that it looks like a benign traffic stream.
Active Directory Enumeration & Attacks
Medium
Path Sections 36 Sections
Reward: +20
Active Directory (AD) is the leading enterprise domain management suite, providing identity and access management, centralized domain administration, authentication, and much more. Due to the many features and complexity of AD, it presents a large attack surface that is difficult to secure properly. To be successful as infosec professionals, we must understand AD architectures and how to secure our enterprise environments. As Penetration testers, having a firm grasp of what tools, techniques, and procedures are available to us for enumerating and attacking AD environments and commonly seen AD misconfigurations is a must.
Linux Privilege Escalation
Easy
Path Sections 15 Sections
Reward: +20
Privilege escalation is a crucial phase during any security assessment. During this phase, we attempt to gain access to additional users, hosts, and resources to move closer to the assessment's overall goal. There are many ways to escalate privileges. This module aims to cover the most common methods emphasizing real-world misconfigurations and flaws that we may encounter in a client environment. The techniques covered in this module are not an exhaustive list of all possibilities and aim to avoid extreme "edge-case" tactics that may be seen in a Capture the Flag (CTF) exercise.
Windows Privilege Escalation
Medium
Path Sections 31 Sections
Reward: +20 UPDATED
After gaining a foothold, elevating our privileges will provide more options for persistence and may reveal information stored locally that can further our access in the environment. Enumeration is the key to privilege escalation. When you gain initial shell access to the host, it is important to gain situational awareness and uncover details relating to the OS version, patch level, any installed software, our current privileges, group memberships, and more. Windows presents an enormous attack surface and, being that most companies run Windows hosts in some way, we will more often than not find ourselves gaining access to Windows machines during our assessments. This covers common methods while emphasizing real-world misconfigurations and flaws that we may encounter during an assessment. There are many additional "edge-case" possibilities not covered in this module. We will cover both modern and legacy Windows Server and Desktop versions that may be present in a client environment.
Using Web Proxies
Easy
Path Sections 15 Sections
Reward: +20
Web application penetration testing frameworks are an essential part of any web penetration test. This module will teach you two of the best frameworks: Burp Suite and OWASP ZAP.
Attacking Web Applications with Ffuf
Easy
Path Sections 13 Sections
Reward: +10
This module covers the fundamental enumeration skills of web fuzzing and directory brute forcing using the Ffuf tool. The techniques learned in this module will help us in locating hidden pages, directories, and parameters when targeting web applications.
Login Brute Forcing
Easy
Path Sections 11 Sections
Reward: +20
Learn how to brute force logins for various types of services and create custom wordlists based on your target.
Cross-Site Scripting (XSS)
Easy
Path Sections 10 Sections
Reward: +20
Cross-Site Scripting (XSS) vulnerabilities are among the most common web application vulnerabilities. An XSS vulnerability may allow an attacker to execute arbitrary JavaScript code within the target's browser and result in complete web application compromise if chained together with other vulnerabilities. This module will teach you how to identify XSS vulnerabilities and exploit them.
Session Security
Medium
Path Sections 14 Sections
Reward: +20
Maintaining and keeping track of a user's session is an integral part of web applications. It is an area that requires extensive testing to ensure it is set up robustly and securely. This module covers the most common attacks and vulnerabilities that can affect web application sessions, such as Session Hijacking, Session Fixation, Cross-Site Request Forgery, Cross-Site Scripting, and Open Redirects.
SQL Injection Fundamentals
Medium
Path Sections 17 Sections
Reward: +10
Databases are an important part of web application infrastructure and SQL (Structured Query Language) to store, retrieve, and manipulate information stored in them. SQL injection is a code injection technique used to take advantage of coding vulnerabilities and inject SQL queries via an application to bypass authentication, retrieve data from the back-end database, or achieve code execution on the underlying server.
SQLMap Essentials
Easy
Path Sections 11 Sections
Reward: +20
The SQLMap Essentials module will teach you the basics of using SQLMap to discover various types of SQL Injection vulnerabilities, all the way to the advanced enumeration of databases to retrieve all data of interest.
Blind SQL Injection
Hard
Path Sections 16 Sections
Reward: +100
In this module, we cover blind SQL injection attacks and MSSQL-specific attacks.
Advanced SQL Injections
Hard
Path Sections 12 Sections
Reward: +100
This module covers advanced SQL injection techniques with a focus on white-box testing, Java/Spring and PostgreSQL.
File Inclusion
Medium
Path Sections 11 Sections
Reward: +10
File Inclusion is a common web application vulnerability, which can be easily overlooked as part of a web application's functionality.
File Upload Attacks
Medium
Path Sections 11 Sections
Reward: +20
Arbitrary file uploads are among the most critical web vulnerabilities. These flaws enable attackers to upload malicious files, execute arbitrary commands on the back-end server, and even take control over the entire server and all web applications hosted on it and potentially gain access to sensitive data or cause a service disruption.
Command Injections
Medium
Path Sections 12 Sections
Reward: +20
Command injection vulnerabilities can be leveraged to compromise a hosting server and its entire network. This module will teach you how to identify and exploit command injection vulnerabilities and how to use various filter bypassing techniques to avoid security mitigations.
Broken Authentication
Medium
Path Sections 14 Sections
Reward: +20
Authentication is probably the most straightforward and prevalent measure used to secure access to resources, and it's the first line of defense against unauthorized access. Broken authentication is currently listed as #7 on the 2021 OWASP Top 10 Web Application Security Risks, falling under the broader category of Identification and Authentication failures. A vulnerability or misconfiguration at the authentication stage can devastatingly impact an application's overall security.
Web Attacks
Medium
Path Sections 18 Sections
Reward: +20
This module covers three common web vulnerabilities, HTTP Verb Tampering, IDOR, and XXE, each of which can have a significant impact on a company's systems. We will cover how to identify, exploit, and prevent each of them through various methods.
HTTPs/TLS Attacks
Medium
Path Sections 15 Sections
Reward: +100
This module covers details on Transport Layer Security (TLS) and how it helps to make HTTP secure with the widely used HTTPS. That includes how TLS works, how TLS sessions are established, common TLS misconfigurations, as well as famous attacks on TLS. We will discuss how to identify, exploit, and prevent TLS attacks.
HTTP Attacks
Hard
Path Sections 18 Sections
Reward: +100
This module covers three HTTP vulnerabilities: CRLF Injection, HTTP Request Smuggling, and HTTP/2 Downgrading. These vulnerabilities can arise on the HTTP level in real-world deployment settings utilizing intermediary systems such as reverse proxies in front of the web server. We will cover how to identify, exploit, and prevent each of these vulnerabilities.
Abusing HTTP Misconfigurations
Hard
Path Sections 20 Sections
Reward: +100
This module covers three common HTTP vulnerabilities: Web Cache Poisoning, Host Header Vulnerabilities, and Session Puzzling or Session Variable Overloading. These vulnerabilities can arise on the HTTP level due to web server misconfigurations, other systems that have to be considered during real-world deployment such as web caches, or coding mistakes in the web application. We will cover how to identify, exploit, and prevent each of these vulnerabilities.
Attacking Common Applications
Medium
Path Sections 33 Sections
Reward: +20 UPDATED
Penetration Testers can come across various applications, such as Content Management Systems, custom web applications, internal portals used by developers and sysadmins, and more. It's common to find the same applications across many different environments. While an application may not be vulnerable in one environment, it may be misconfigured or unpatched in the next. It is important as an assessor to have a firm grasp of enumerating and attacking the common applications discussed in this module. This knowledge will help when encountering other types of applications during assessments.
Web Service & API Attacks
Medium
Path Sections 13 Sections
Reward: +20
Web services and APIs are frequently exposed to provide certain functionalities in a programmatic way between heterogeneous devices and software components. Both web services and APIs can assist in integrating different applications or facilitate separation within a given application. This module covers how to identify the functionality a web service or API offers and exploit any security-related inefficiencies.
Hacking WordPress
Easy
Path Sections 16 Sections
Reward: +20
WordPress is an open-source Content Management System (CMS) that can be used for multiple purposes.
Documentation & Reporting
Easy
Path Sections 8 Sections
Reward: +20
Proper documentation is paramount during any engagement. The end goal of a technical assessment is the report deliverable which will often be presented to a broad audience within the target organization. We must take detailed notes and be very organized in our documentation, which will help us in the event of an incident during the assessment. This will also help ensure that our reports contain enough detail to illustrate the impact of our findings properly.

Information Security Foundations

Information Security is a field with many specialized and highly technical disciplines. Job roles like Penetration Tester & Information Security Analyst require a solid technical foundational understanding of core IT & Information Security topics. This skill path is made up of modules that will assist learners in developing &/or strengthening a foundational understanding before proceeding with learning the more complex security topics. Every long-standing building first needs a solid foundation. Welcome to Information Security Foundations.

Easy Path Sections 191 Sections
Required: 200
Reward: +120
Path Modules
Introduction to Academy
Fundamental
Path Sections 8 Sections
Reward: +10
This module is recommended for new users. It allows users to become acquainted with the platform and the learning process.
Learning Process
Fundamental
Path Sections 20 Sections
Reward: +10
The learning process is one of the essential and most important components that is often overlooked. This module does not teach you techniques to learn but describes the process of learning adapted to the field of information security. You will learn to understand how and when we learn best and increase and improve your learning efficiency greatly.
Setting Up
Fundamental
Path Sections 9 Sections
Reward: +10
This module covers topics that will help us be better prepared before conducting penetration tests. Preparations before a penetration test can often take a lot of time and effort, and this module shows how to prepare efficiently.
Linux Fundamentals
Fundamental
Path Sections 30 Sections
Reward: +10 UPDATED
This module covers the fundamentals required to work comfortably with the Linux operating system and shell.
Windows Fundamentals
Fundamental
Path Sections 14 Sections
Reward: +10
This module covers the fundamentals required to work comfortably with the Windows operating system.
Introduction to Windows Command Line
Easy
Path Sections 23 Sections
Reward: +10
As administrators and Pentesters, we may not always be able to utilize a graphical user interface for the actions we need to perform. Introduction to Windows Command Line aims to introduce students to the wide range of uses for Command Prompt and PowerShell within a Windows environment. We will cover basic usage of both key executables for administration, useful PowerShell cmdlets and modules, and different ways to leverage these tools to our benefit.
Introduction to Bash Scripting
Easy
Path Sections 10 Sections
Reward: +10
This module covers the basics needed for working with Bash scripts to automate tasks on Linux systems. A strong grasp of Bash is a fundamental skill for anyone working in a technical information security role. Through the power of automation, we can unlock the Linux operating system's full potential and efficiently perform habitual tasks.
Introduction to Networking
Fundamental
Path Sections 21 Sections
Reward: +10 UPDATED
As an information security professional, a firm grasp of networking fundamentals and the required components is necessary. Without a strong foundation in networking, it will be tough to progress in any area of information security. Understanding how a network is structured and how the communication between the individual hosts and servers takes place using the various protocols allows us to understand the entire network structure and its network traffic in detail and how different communication standards are handled. This knowledge is essential to create our tools and to interact with the protocols.
Intro to Network Traffic Analysis
Medium
Path Sections 15 Sections
Reward: +10
Network traffic analysis is used by security teams to monitor network activity and look for anomalies that could indicate security and operational issues. Offensive security practitioners can use network traffic analysis to search for sensitive data such as credentials, hidden applications, reachable network segments, or other potentially sensitive information "on the wire." Network traffic analysis has many uses for attackers and defenders alike.
Introduction to Active Directory
Fundamental
Path Sections 16 Sections
Reward: +10
Active Directory (AD) is present in the majority of corporate environments. Due to its many features and complexity, it presents a vast attack surface. To be successful as penetration testers and information security professionals, we must have a firm understanding of Active Directory fundamentals, AD structures, functionality, common AD flaws, misconfigurations, and defensive measures.
Introduction to Web Applications
Fundamental
Path Sections 17 Sections
Reward: +10
In the Introduction to Web Applications module, you will learn all of the basics of how web applications work and begin to look at them from an information security perspective.
Web Requests
Fundamental
Path Sections 8 Sections
Reward: +10
This module introduces the topic of HTTP web requests and how different web applications utilize them to communicate with their backends.