More than one billion Yahoo accounts breached in hack
Hackers stole data from more than one billion Yahoo accounts, the company has said.
The California company said the data breach occurred in August 2013 and is different to the one disclosed in September that affected 500 million users.
Yahoo, which is being acquired by Verizon, said an unauthorised third party had stolen the data in the latest breach and that it was working closely with law enforcement.
It said user account information stolen in the breach may have included names, email addresses, telephone numbers, dates of birth, hashed passwords and, in some cases, unencrypted security questions and answers.
Payment card data and bank account information were not stored in the system believed to be affected, the company said.
The latest hack revelation raises questions about whether Verizon will try to change the terms of its $4.8 billion proposed acquisition of the company.