Challenge Category: OSINT
The author is a professional person and has a medium to run his own blog. He likes the white colour the most. Can you spot the flag?
- I created this challenge as part of DC9111 2021 CTF.
- This challenge includes OSINT and Steganography, that’s why its name is OSINTEGO.
- Open Source INTelligence (OSINT) is the practice of collecting information from publicly available sources.
- Whitespace Steganography has been used here to hide the flag. A whitespace character does not correspond to a visible mark, but typically does occupy an area on a page. Read more about Whitespace character here.
How to Solve
1). “Professional” means a professional platform which means LinkedIn and author name is given in the challenge, so go to LinkedIn of author - https://www.linkedin.com/in/cybersapien/
2). We can see 3 blogs links in the featured section.
3). “own blog” means blog hosted on own domain, so go to cybersapien.tech.
4). See the source code of the web page.
5). “white colour” means White Space Steganography. Select all the text and we can see a weird thing that a long blank line selected as a text.
6). Copy this line, and paste it in Sublime Text or VS code editor.
7). Select the pasted text, this will highlight the text.
8). We can see tabs (arrow) and spaces.
9). Tabs and spaces can be converted to binary, tabs to 0 and spaces to 1, using the following Python script-
pasted_text = " " print(pasted_text.replace('\t', '0').replace(' ', '1'))
10). We will get a text containing 0’s and 1’s, we can convert it to ASCII using website - https://www.convertbinary.com/to-text.
This is the flag.
This confirms that we have successfully completed the challenge.
I hope, this post helped you to solve this CTF challenge easily and you must have learned something new.
Feel free to contact me for any suggestions and feedbacks. I would really appreciate those.
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