Rating:
This is a Unity video game. When we open it, we see that a death screen appears within 0.5 seconds after a robot sees us and to get the flag we must kill all the robots.
The first thing we have to do is open the Assembly-CSharp.dll file with a .NET decompiler, in my case to patch it, I use DnSpy.
We will navigate to PlayerControl and then to the method Die()
To patch it, we simply deactivate the death screen, adding "false" and instead of invoking the Respawn we invoke anything else, for example, HitRobot, so when the robots kill us, we will not reappear and we will kill the robots easily.
When we heard the audio, we knew perfectly that it was an SSTV signal, so we used RX-SSTV to decode it and generate an image.
When we look at the file strings, we see multiple encodings.
To decode it, I used CyberChef Base64> Base32> Hex.
This gives us the next hint: Maybe B.F. stands for something other than best friend :)
At first we thought it was something related to Brainfuck Steganography, but no, after thinking for a long time we realized that it was the acronym for BruteForce, so we used stegcracker (Steghide BruteForce) to decode the image.
Quickly give us an output with the password "celeste".
it is a Base85 encoding, when we decode it, we will get the flag.
This challenge was quite easy, we just opened the file provided by the challenge with IDA. If we see the main function graphically, we will quickly get the flag.
