I created ransomware and successfully used it in different attacks.
Video demo: https://youtu.be/7_7jK8z_2rk
I improved my ransomware afterwards by using a TLS socket to conceal the network traffic. I captured the traffic before and after I executed the attack. I have screenshots of the plaintext vs the ciphertext in a pdf file in this directory.
In a different directory, I further improved my ransomware by making it portable. I made it portable so that it can execute in any environment without dependencies. I used staticX to make it portable. The portable version is rc_client_wrapped.