Russian Cyber Criminal Named as Source of Massive Collection 1 Data Dump

Recorded Future reports that a massive set of aggregated credentials—most notably "Collection 1" (≈773 million records) and several additional archives totaling up to billions of records—was being shared on Russian-language hacker forums; researchers observed a forum user, "C0rpz", as a likely originator, though confidence is rated medium. The collections largely comprise previously leaked credentials combined into large archives, and their broad availability raises significant risk of credential-stuffing and other automated account takeover attacks.