Signals

This is pretty barebones…sorry lol

Some amateur radio hackers captured a strange signal from space. A first analysis indicates similarities with signals transmitted by the ISS. Can you decode the signal and get the information?

Steps

1. Unzip the file w password hackthebox (given) to get the Signal.wav file
2. First I went to dcode to run the file through spectral analysis, but I didn’t find much there
3. Looking at the challenge description again, the ISS is mentioned
4. After exactly one google search (“iss signal transmission file type”), I found that the ISS uses the PD-120 SSTV format (sstv is the important bit)
5. Now I looked for tools used to decode SSTV images, and I ended up with mmsstv
6. The webpage was a lil sketch but I haven’t seen signs of malware since downloading it so it was probably fine
7. To send the sound from the file directly to mmsstv, we need a digital cable and vlc player
8. I used this article for help with setting everything up
9. After the file is done playing, you should have a red background, skull and crossbones, and readable flag on your screen
10. If you’re having issues, you can also try rxsstv HTB{5l0w-5c4n_73l3v1510n_h4m_r4d10_XXXXXX}