Short laugh clips like this one spread through meme pages, soundboards and short video edits because they need no context to understand. A single ha ha works across languages and can be reused under almost any joke, which is why creators keep it alongside other reaction laughs such as the baby laughing meme and the cat laugh meme. It has no confirmed original source, so its history is really a history of reuse, passed between chats and edits as a quick, universal way to say something was funny.