All started with an image
The challenge gives an image to start with. Searching in it we found a trailing string that was a link to a file in dropbox.
A protected zip file
The file we got from that dropbox link is a protected zip. After a while we decided to throw John the ripper with the Rockyou dictionary and it worked! Now we have a corrupted file, let's continue.
Fixing things up
Looking at the file magic bits we can see that is probably a jpeg image. Fixing the header allow us to open the image and get the flag: