Introduction

In this post, We covered Cryptography and Steganography Challenges as part of TryHackMe CTF collection Vol.1 Part 3.

The main objective of the room is to test your CTF skills. For your information, vol.1 consists of 20 tasks and all the challenges are extremely easy. Stay calm and Capture the flag. 🙂

Tasks Covered : Task 16,17,18,19,20,21

How Good is Your Listening Skill?

Next up, I had a QR code that was supposed to lead me to a flag. The hint was that it was an audio file. I used an online QR code decoder, and sure enough, it gave me a SoundCloud link. I played the audio, and the flag, “SOUNDINGQR”, was spoken aloud.

Dig Up the Past

This challenge was all about finding a flag on a website, but with a twist. I had to look at a past version of the site from a specific date. To do this, I used the Wayback Machine. I entered the website’s URL and navigated to the snapshot from January 2, 2020. After a little digging on the archived page, I found the flag.

Uncrackable

Here, I was given an encrypted string and a hint that it was a Vigenere cipher. I turned to CyberChef to help me crack it. The first key I tried was “TRYHACKME” (in all caps), which is the flag format for the platform. This gave me a new string, which I then decrypted again using the key “thmthm”. That second decryption revealed the final flag.

Small Bases

This was a quick one. I had a decimal string that I needed to convert to find the flag. I used an online converter to change the decimal string to hexadecimal, and then converted the hexadecimal output to ASCII. That gave me the flag.

Read the Packet

For my final challenge, I had to analyze a network capture file. I opened the .pcap file in Wireshark and filtered for HTTP traffic. I then followed the TCP stream of an HTTP response to a /flag request and found the flag hidden within the stream.

Technical Commands

Throughout the video, I used a few commands in the terminal. Here they are:

  • wget https://github.com/baku89/stegsolve/releases/download/v1.3/stegsolve.jar
  • chmod +x stegsolve.jar
  • mkdir bin
  • mv stegsolve.jar bin
  • mv dark.png bin
  • java -jar stegsolve.jar
  • java -jar bin/stegsolve.jar

TryHackMe CTF collection Vol.1 Part 3 Room Answers

What does the flag said?

What does the bot said?

Did you found my past?

The deciphered text

What is the flag?

Did you captured my neighbor’s flag?

 

Video Walkthrough

 

About the Author

Mastermind Study Notes is a group of talented authors and writers who are experienced and well-versed across different fields. The group is led by, Motasem Hamdan, who is a Cybersecurity content creator and YouTuber.

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