Yahoo eventually decided to inform its service users about the size of the latest violations and leaks.
The first hack apparently took place in August 2013 and leaked names, email addresses, phone numbers, dates of birth, hashed passwords accesss (with MD5) and in some cases, encrypted or unencrypted security questions and answers.
Plain text passwords and credit card information paymentare not reported by the company.
Yahoo said in a statement that it had "alerted affected users" and that it had "taken steps to secure the accounts by requiring users to change their passwords."
And yes, Yahoo admitted that the above hack is different from the breach and leakage of 500 million accounts which was revealed in September of this year.
However, the company adds that those responsible are themselves hackers who committed the first violation.
If you are one of those who still have Yahoo accounts, change it code your access directly, or register at company authentication service.
More information in the official announcement: