It's mentioned in one of the first references in this article: https://boehs.org/node/everything-i-know-about-the-xz-backdoor https://boehs.org/node/everything

It's mentioned in one of the first references in this article: https://boehs.org/node/everything-i-know-about-the-xz-backdoor https://boehs.org/node/everything-i-know-about-the-xz-backdo... IRC activity