Until the NPD breach, the Yahoo data breach in 2013 stood as the worst cyberattack in history. The first attack occurred in 2013, with more to follow over the next three years. Only after Verizon bought out Yahoo in 2017, did the actual number of records affected come to light. It was determined that all 3 billion of Yahoo's accounts were affected. That particular breach included the theft of names, email addresses, phone numbers and birthdates, but did not involve financial information.