> ## Documentation Index
> Fetch the complete documentation index at: https://www.nthsec.com/llms.txt
> Use this file to discover all available pages before exploring further.

# CTF Writeups: HackSmarter, HackTheBox, and TryHackMe Walkthroughs

> Step-by-step CTF writeups from NTHSec, organized by platform and difficulty. HackSmarter, HackTheBox, and TryHackMe challenges explained for beginners.

These are my Capture the Flag walkthroughs, written so you can follow along even if it's your first CTF. Browse by platform or by difficulty below. Every writeup explains not just what I did, but why.

> [!NOTE]
>
> I only publish writeups for retired machines and challenges that platforms allow writeups for. Please do the same.

## By Platform

**HackSmarter**

> **[HackSmarter: Casino](https://www.nthsec.com/ctf/hsm-casino.md)**
>
> Medium · Linux · Web

> **[HackSmarter: CTOS](https://www.nthsec.com/ctf/hsm-ctos.md)**
>
> Medium · Multi-Machine · Active Directory

> **[HackSmarter: Walnut](https://www.nthsec.com/ctf/hsm-walnut.md)**
>
> Easy · Linux

**HackTheBox**

> **[HackTheBox: Underpass](https://www.nthsec.com/ctf/htb-underpass.md)**
>
> Easy · Linux · SNMP enumeration, default credentials, and a mosh-server privilege escalation

**TryHackMe**

> **[TryHackMe: Ledger](https://www.nthsec.com/ctf/thm-ledger.md)**
>
> Hard · Active Directory · ADCS · LDAP Enumeration

## By Difficulty

**Easy**

> **[HackTheBox: Underpass](https://www.nthsec.com/ctf/htb-underpass.md)**
>
> HackTheBox · Linux · SNMP enumeration, default credentials, and a mosh-server privilege escalation

> **[HackSmarter: Walnut](https://www.nthsec.com/ctf/hsm-walnut.md)**
>
> Easy · Linux

**Medium**

> **[HackSmarter: Casino](https://www.nthsec.com/ctf/hsm-casino.md)**
>
> HackSmarter · Coming soon

> **[HackSmarter: CTOS](https://www.nthsec.com/ctf/hsm-ctos.md)**
>
> Medium · Multi-Machine · Active Directory

**Hard**

> **[TryHackMe: Ledger](https://www.nthsec.com/ctf/try-hack-me-ledger-walkthrough)**
>
> TryHackMe · Active Directory · ADCS · LDAP Enumeration


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