Steganography - Echoes of the Unknown

Not everything is heard—some things must be seen.

Solution :

A file.wav audio file was attached with the challenge. Played it, but unfortunately no hints or leads. But it sounded more like lines and dots, continuous beep for a while and then a short beep. Guessed it to be morse code. Therefore I opened sonic visualizer and viewed the spectrogram version of the .wav file.

Yes, it was a morse code.

Opened morse code decoder online and then got the flag.

Flag: VishwaCTF{CR4CK3D7H3C0D3}