Yes, one billion accounts.
The company disclosed today that it has discovered a breach of more than one billion user accounts that occurred in August 2013. The breach is believed to be separate and distinct from the theft of data from 500 million accounts that Yahoo reported this September.
Troublingly, Yahoo’s chief information security officer Bob Lord says that the company hasn’t been able to determine how the data from the one billion accounts was stolen. “We have not been able to identify the intrusion associated with this theft,” Lord wrote in a post announcing the hack.
“The stolen user account information may have included names, email addresses, telephone numbers, dates of birth, hashed passwords (using MD5) and, in some cases, encrypted or unencrypted security questions and answers,” Lord added.
Yep, there was another hack but from 2013 which resulted in 1 billion accounts being targeted, thus breaking Yahoo's previous record of 500 million and became the largest data breach in history.
https://techcrunch.com/2016/12/14/yahoo-discloses-hack-of-1-billion-accounts/