Where does Flexxon obtain its ransomware to perform testing?

The dark web, where Flexxon’s daily mail consists of over 104 ransomwares. Should there be a new ransomware on the market, Flexxon will study it to study if there are any new patterns. Of the 104 ransomwares, 10% of it are the same ransomware but of different variant (eg: WannaCry).