Post cover image

August 27, 2026

Hello Hackers — Linux Luminarium Part 1

Introduction

By mayhack

3 min read

Hello Hackers — Linux Luminarium Part 1

Introduction

Hello everyone! 👋

In this series, we are going to solve the Linux labs from PWN College's Linux Luminarium module by module.

Each writeup will cover one complete module. We won't just collect the flags — we'll also understand what the command does, why we are using it, and other useful ways to get the same result wherever possible.

The main goal is to make these writeups useful for both learning Linux from scratch and revising Linux basics.

After completing the Linux Luminarium modules, we'll also move towards the Bandit labs for more hands-on Linux practice.

Let's start with our first module: Hello Hackers.

Intro to Commands

Challenge Description

In this challenge, we are introduced to the most basic concept of the Linux command line: running a command.

When we type a command and press Enter, the shell executes it and then shows the prompt again, ready for the next command.

For example:

hacker@dojo:~$ whoami
hacker
hacker@dojo:~$

Here, whoami is the command, and it prints the username of the current user.

The challenge asks us to invoke the hello command to get the flag.

One important thing to remember is that Linux commands are case-sensitive. hello and HELLO are different.

Solution

We simply run the command mentioned in the challenge:

hacker@hello~intro-to-commands:~$ hello

The terminal gives us:

Success! Here is your flag:
pwn.college{MtKfbFfisGaUCtBRQVxEpUq4zMG.QX3YjM1wiM2QDO1EzW}

Why Does It Work?

The shell reads the command we entered:

hello

and executes the corresponding program/command.

Once it finishes, the shell returns to the prompt.

So the basic flow is:

Enter command
     ↓
Shell executes it
     ↓
Output is displayed
     ↓
Prompt appears again

Learning

The main thing to understand here is how a Linux command line works.

whoami

is a command, and its output tells us who the current user is.

We also learned that Linux commands are case-sensitive.

Intro to Arguments

Challenge Description

Now we move one step further and learn about arguments.

Arguments are additional pieces of information that we pass to a command.

For example:

hacker@dojo:~$ echo Hello
Hello

Here:

echo   → command
Hello  → argument

We can also pass multiple arguments:

hacker@dojo:~$ echo Hello Hackers!
Hello Hackers!

Here Hello and Hackers! are both arguments.

The challenge asks us to run the hello command with a single argument: hackers.

Solution

We run:

hacker@hello~intro-to-arguments:~$ hello hackers

The challenge responds:

Success! Here is your flag:
pwn.college{0tCU0sGg2VOGrM-qBUAz91FaFMC.QX4YjM1wiM2QDO1EzW}

Breaking Down the Command

Our command is:

hello hackers

The shell understands it as:

hello   → command
hackers → argument

So the general structure is:

command argument

We can also have multiple arguments:

command argument1 argument2 argument3

For example:

ls /home

Here ls is the command and /home is the argument telling ls which directory we want to work with.

Learning

The important point is that arguments give extra information to a command.

You will see this constantly in Linux.

For example:

ls /home
cat file.txt
cd /tmp

In all of these, the words after the command provide additional information.

Command History

Challenge Description

When working in a terminal, we may have to type many commands.

Typing the same command again and again can be annoying, so the shell keeps a history of commands that we have entered.

We can move through this history using the Up and Down arrow keys.

The challenge specifically puts the flag into the command history. Our task is simply to retrieve it.

Solution

After opening the terminal, press the Up Arrow (↑) key.

The previous entry appears:

hacker@hello~command-history:~$ the flag is pwn.college{EGR6ne9ezALWoGQoPILvWh-tKQ0.0lNzEzNxwiM2QDO1EzW}

That's it — the flag was already stored in the shell history.

Another Way to View History

Instead of using the arrow key, we can use:

history

This displays previously executed commands.

For example:

$ history
1  whoami
2  ls
3  pwd
4  echo Hello

We can also search the history using grep.

For example:

history | grep pwn.college

This can be useful when the history is very long.

Learning

Remember these two useful methods:

↑ / ↓     → move through command history
history   → display command history

Command history is useful for quickly reusing commands.

It can also be interesting during security testing because users sometimes accidentally leave sensitive information in their shell history.

Key Learnings

After completing the Hello Hackers module, we learned three basic Linux concepts.

Commands

A command tells the shell what we want to execute.

Example:

whoami

Arguments

Arguments provide additional information to a command.

Example:

hello hackers

Here hello is the command and hackers is the argument.

Command History

The shell remembers previously entered commands.

We can access them using:

↑ / ↓

or:

history

One Important Rule

Linux is case-sensitive.

These are different:

hello
Hello
HELLO

So always pay attention to spelling and capitalization.

Conclusion

The Hello Hackers module is a simple introduction to the Linux command line.

We learned how to execute commands, pass arguments, and use command history.

These concepts may look basic, but they are the foundation for the more advanced Linux commands and techniques we will use in the upcoming modules.

This is just Part 1 of the Linux Luminarium series.

Check my profile for the other parts and upcoming Linux module writeups. 🚀

📬 Stay Connected

If you found this helpful and want to learn more about web security, hands-on labs, feel free to follow me for upcoming posts.

✍️ Follow me for more cybersecurity write-ups 🔗 LinkedIn — codermayank 📸 Instagram — @mayhack_

Tags: #BugBounty #EthicalHacking #CyberSecurity #Linux #PwnCollege #CTF #CaptureTheFlag #LinuxSecurity #PenetrationTesting #WebSecurity #InfoSec