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.
