File Carving 3
Read through this writeup. This one is hard to do now because it was mostly on Twitter and things have disappeared, so just read through it to understand how it worked.
Tons of CTF challenges use sites like Twitter or Facebook, or even more niche sites like dating apps to host challenges and make them more interesting.
https://the-bilal-rizwan.medium.com/intigriti-ctf-writeup-737009900a42