Text hiding inside a picture
An image file carries readable text in a metadata chunk and after its end marker. Use file and strings to find the comment, the author, and the flag.
Briefing
The challenge is ~/challenge/sunset.png. It opens as a normal picture.
Many formats allow text chunks, and most viewers ignore bytes after the end of the image. strings prints every run of four or more printable characters, which is often enough.
ctf-box · CTF warm-ups
Type help for the command list and objectives for your tasks. Everything runs in this browser.
Up and down arrows walk your history. Ctrl+L clears the screen. Try help, ls, and objectives.