Yahoo says hackers stole information from about 500 million users in 2014 in what appears to be the largest publicly disclosed cyber-breach in history.
The breach included swathes of personal information including names and emails as well as “unencrypted security questions and answers”.
It did not include any credit card data, the site said, adding it believed the attack was state-sponsored.
In July, Yahoo was sold to US telecoms giant Verizon for $4.8bn (£3.7bn). The FBI has confirmed it is investigating the attack.(BBC,2016)