Alien Transmission 1

I was listening to my radio the other day and received this strange message… I think it came from an alien?

Files

• squeakymusic.wav

Solution

People who have solved m00walk problem from picoCTF 2019 would immediately recognize this audo file.

The audio is a SSTV signal which are generally used to transmit images from space to earth. I used the program from this, http://users.belgacom.net/hamradio/rxsstv.htm to decode the signal to give an image. The program would be listening for a signal and we just need to play the audio sample to it. The RX would be automatically identified. The signal gives us the following image:

Flag

rgbCTF{s10w_2c4n_1s_7h3_W4V3}