A fun one by @BusesCanfly! Challenge description says
```"I sure do love painting :)"(Note: sampled at 44.1 kHz) ```
and has a gigantic mystery.zip file download. Inside the zip file is a file named thats_freq_ky.iq. iq files are radio captures stored in iq mode. Based on the title of the challenge, I did some quick google searching for “radio painting” and came across this [hackaday](https://hackaday.com/2015/08/22/spectrum-painting-on-2-4-ghz/) article from 2015 about paint pictures with radio frequencies. So naturally, based on this information, we want to open it in a viewer for RF files. My weapon of choice for this challenge is [HDSDR](https://www.hdsdr.de/), but first we need to convert it into something the application can ingest. You can also use [SDR#](https://airspy.com/download/) but I personally like using HDSDR more. Using [iqToSharp](https://github.com/Marcin648/iqToSharp) I converted the iq file to a wav file to open in HDSDR using
`iqToSharp_x64.exe -i .\thats_freq_ky.iq -f 44100 -o solve.wav`
At first glance we can see the following:
![](https://newyork167.github.io/images/ctf/2022/nahamcon/picasso1.png)
Certainly looks like they are “painting” on the airwaves! I basically sat through all three minutes of it looking for interesting spots like
![](https://newyork167.github.io/images/ctf/2022/nahamcon/picasso2.png)
Ultimately the flag ended up being near the end but we can clearly see that there is a flag!
![](https://newyork167.github.io/images/ctf/2022/nahamcon/picasso3.png)
![](https://newyork167.github.io/images/ctf/2022/nahamcon/picasso4.png)
Nestled in the same airwaves as John Hammond and Lord Foog we have our flag! Finally, I reversed the wav file to get things looking right side up for me to more easily clean things up using
`sox -V solve.wav_44100Hz_IQ.wav solve_reverse.wav reverse`
and there we have it!
![](https://newyork167.github.io/images/ctf/2022/nahamcon/picasso5.png)