Tags: spectrogram 

Rating: 4.5

## Bad Apple
Someone stumbled upon this file in a secure server. What could it mean?
file: https://dctf.dragonsec.si/files/230afaac6d3b52b608268829e8aa11d0/Bad_Apple.mp4

## Solution:
I downloaded the file and opened and heard some weird sound in the middle. So extracted audio and analysed in sonic vision and added A spectrogram was used to find a QR code.

![image](https://user-images.githubusercontent.com/78896740/118483703-f82f5a00-b733-11eb-9b1e-d2d4637ca63e.png)![image](https://user-images.githubusercontent.com/78896740/118483934-43e20380-b734-11eb-9114-c45f4a2af5c6.png)

converted into black and white and scanned QR code and got the flag.

flag:`dctf{sp3tr0gr4msAreCo0l}`

Original writeup (https://github.com/victim1307/CTF/blob/main/DCTF2021/badapple.md).