Once bought from ValidCC, cybercriminals used automated tools to exploit the compromised accounts:

The history of ValidCC provides a stark look into modern cybersecurity threats. It highlights the mechanics of e-commerce data skimming, the operations of sophisticated threat actors, and the eventual dismantling of illicit digital storefronts by global law enforcement. What Was ValidCC?

(and its numerous domain variants like ValidCC.tw and ValidCC.cm) refers to one of the most notorious dark web payment card marketplaces in cybercrime history. Operated by an advanced cybercriminal group, the platform functioned as a primary hub for buying and selling stolen credit card data.