dCTF 2021 - Bad Apple | Steg
Bad Apple
Someone stumbled upon this file in a secure server. What could it mean?
Downloadable audio file
Solution
About halfway through the song, there will be weird static noise.
Examining the audio file using Spectrogram, we can see that there is a hidden QR code !
Scanning the QR code with a normal QR code app on the phone will lead us straight to the flag.
Flag: dctf{sp3ctr0gr4msAreCo0l}