AASTU CSC CTF | Hidden in Plain Sight 01

Cyber Night CTF Day 01 Walkthrough Challenge 1

Level: Easy 🟢
Challenge Link: Hidden in plain sight
Technique: EXIF-based Steganography
Tool: Exiftool
Point: 100

Description:

What if your eyes are missing more than just pixels? Within an ordinary file lies an extraordinary secret. Steganography hides messages in plain sight — can you spot the hidden truth?

Concept Behind the Challenge

💡 What Is EXIF-based Steganography?

EXIF (Exchangeable Image File Format) is a standard for storing metadata in image files, such as camera details, GPS coordinates, date, and other properties. EXIF-based steganography involves hiding information, such as a flag, within this metadata, which is invisible in the image itself but can be extracted with tools like ExifTool.

In this challenge, the flag is hidden inside the metadata of an image file. The key to discovering it lies in extracting and analyzing the EXIF metadata of the image file.

🌐 OSINT Relevance:

EXIF metadata is often overlooked in publicly posted files on social media, blogs, or websites. Attackers may use EXIF-based steganography to embed covert messages in images shared online, making it harder to detect at first glance. For OSINT (Open-Source Intelligence) gathering, analyzing metadata from publicly available images can provide critical information — from hidden messages to location data or even timestamps that reveal more about a target.

This string looks like it is encrypted using base64 from the structure at the end “=”. taking it and decoding it gives us our first flag.

You can also take the encrypted string and go to cyberchef web which is basically a decryption and encryption tools repo.

✅ Flag captured successfully!

flag{h3110_fr0m_th3_0th3r_1ay3r}