A couple of months ago I started the Hack4u platform course called Introduction to Linux and today I have completed it.

Although I was already familiar with Linux, this course has helped me to learn new techniques and procedures, as well as to learn how to script in bash.

The course has 15 hours of content, focused in a very practical and simple way, where you are asked questions and exercises that you have to solve yourself. That is why between some things and others I have ended up dedicating about 50 hours of real time to this course.

Without a doubt I found it a very complete course and I would recommend it, not only to those interested in cybersecurity, but to anyone interested in handling Linux well.

The course content is detailed below:


  • Welcome to the course
  • Operating systems for pentesting
  • Creating a new virtual machine
  • Installing the operating system


  • Linux Basic Commands
  • Stderr-stdout flow control, operators and background processes.
  • File descriptors
  • Reading and interpreting permissions.
  • Assigning Permissions
  • Permissions octal notation
  • Special permissions – Sticky Bit
  • Controlling file attributes in Linux – Chattr and Lsattr
  • Special permissions – SUID and SGID
  • Special privileges – Capabilities
  • System directory structure
  • Use of bashrc and zshrc
  • Upgrading and Upgrading the system
  • Using and managing with Tmux
  • System level searches
  • Creating Bash scripts
  • Using and configuring Kitty
  • Using the Vim editor
  • SSH connections
  • Reading special files
  • Hidden directories and files
  • Detecting file type and format
  • Precise File Searches
  • Data filtering methods
  • Binary file interpretation
  • Base64 encoding and decoding
  • Caesar encryption and use of tr for character translation
  • Creating an automatic recursive file decompressor in Bash
  • Handling key pairs and SSH connections
  • Using netcat to make connections
  • Using encrypted connections
  • Creating our own scanners in Bash
  • Detecting differences between files
  • Executing commands over SSH
  • Abusing SUID privilege for user migration
  • Playing with connections
  • Abusing Cron Tasks
  • Understanding Cron Task Expressions
  • Fuerza bruta aplicada a conexiones
  • Escapando del contexto de un comando
  • Operando con proyectos de Github
  • Argumentos posicionales en Bash

Bash Scripting – Beginner to Advanced

  • Bash Scripting
  • FIRST PROJECT – Creating a search engine
  • SECOND PROJECT – Challenging a Casino Roulette Wheel