In this writeup I will show you how I solved the Rflag challenge from HackTheBox. The challenge is an easy hardware challenge. Let’s start!
Initial Analysis #
After downloading and unzipping the file we can see that it is a .cf32 file. This was the first time I encountered this type of file so I did some research about it. I found out that it is a file that contains complex 32-bit floating point samples. I also found out that we can use rtl_433 to decode this file. So let’s install it.
rtl_433 #
Since I’ve never used this tool before I had to do some research about it. I found out that we can use the -A flag to decode the file. So let’s try it out.
rtl_433 signal.cf32 -A
This is what the output looks like.
In the last line we can see that we have some hex values. Let’s try to decode them using CyberChef.
Our guess was right. We have a flag.
