Aliens have recently landed on the moon and are attempting to communicate with us. Can you figure out what they are trying to tell us?
Hint: On a completely unrelated note, did you know how they trasmitted the first image from the moon?
We’re given an audio file that has the telltale sound of an SSTV transmission. We can decode the stream to get an image which should contain our flag.
The hardest part is finding a decoder and getting it set up, as this is mostly for people processing signals from external input devices.
We settle on Black Cat SSTV and configure our system to pipe the audio file into it:
After the audio is processed, we have our flag: dctf{wHat_ev3n_1s_SSTV}.