It was made by Tvple Eraser on Twitter, who tweets primarily in Korean and had no intention of infecting other people's PCs. Despite the lack of malice behind his actions, he still got a ton of flak since he released its source code on the internet -- anybody can now use it to attack other people's computers. To make up for it, Tvple Eraser replaced the gag malware's code on GitHub with a tool that will let you bypass Rensenware's encryption in case you get infected. While he said that working on the project was fun, he admitted that he made a mistake.

His apology on the GitHub page reads:

"I distributed source code except compiled binary on the web. However, at the point of the distribution, the tragedy was beginning. Maybe It's okay if I remove the encryption/decryption logic before I distribute the source code. then rensenWare can be treated kind of joke program. but I didn't. A number of people blamed me. It's natural. because I made accident definitely wrong. So I pulled down the source code of the rensenWare from the Github, and made this tool. I hope this tool can help the ones who are already affected by rensenWare."

Since his apology doesn't exactly erase Rensenware's source code from the face of the internet, you may want to check out the tool he released. Make sure to watch Touhou's gameplay, as well, so you at least have an idea what you'd be up against.