Wolfire Games created the original Humble Indie Bundle, but they’ve been divested from it for a few years now. From Wikipedia:

The Humble Bundle concept was initially run by Wolfire Games in 2010, but by its second bundle, the Humble Bundle company was spun out to manage the promotion, payments, and distribution of the bundles. In October 2017, the company was acquired by Ziff Davis through its IGN Entertainment subsidiary.

The comment above that Humble’s the ones suing Valve here is inaccurate.