Yahoo! confirmed that it has been hacked. The company said in a press release that the attack has affected 500 million users.
In its official statement, Yahoo! said:
Yahoo! has expected to confirm a massive data breach, and it wasn't revealed until the company made it clear.
The hack attack can be traced back to August 2016 where a hacker called Peace claimed to be selling private information of over 200 million Yahoo! accounts. The stolen data was said to include birthday dates, usernames and passwords, and some including email backups.
Yahoo is also recommending users who haven't changed their passwords since 2014 to change them immediately. The company also encourages users to review their online accounts for suspicious activity and to change their password and security questions and answers for any other accounts on which they use the same or similar information used for their Yahoo! account.