Yahoo hack in 2013 affected accounts of all three billion users

The Yahoo hack in 2013 involved the data of all users, at the time there were about three billion accounts. That has the new owner of Yahoo announced. Yahoo previously stated that it involved one billion accounts.

In a press release, Yahoo writes that during the acquisition by Verizon it came to light that data from all accounts was accessible during the hack in 2013. This would have been revealed through newly obtained information and after investigation by forensic experts. The company is now sending a warning to all Yahoo account users. At the end of 2016, Yahoo announced that it had been hacked in 2013, but then the company stated that the data involved a billion users and only those were warned.

Yahoo has incorporated the new information into its Account Security Update Faq. Last year when the hack was announced, Yahoo had all users who had not changed their passwords since the hack already create a new password. At the time, that was presented as a precaution.

Potentially stolen data includes names, email addresses, phone numbers, dates of birth, and in some cases encrypted and unencrypted security questions and answers. In addition, the hashed passwords that were deemed unsafe with MD5 were also stolen. It was already clear in 2013 that MD5 was not safe. Clear-text passwords have not come into the hands of the attackers, and bank details are not part of the hack, Yahoo says.