1. open the mp3 file using a hex editor and find out it is actually a zip
2. unzip and extract the image from it
3. run the `zsteg` command on this image
4. from the output gather all the base64 text
5. decode it combined and not in parts to get the flag

Original writeup (https://github.com/juke-33/Write-ups/tree/main/BrunnerCTF%202025).