Yahoo has admitted that all three billion of its user accounts were compromised by a data breach in 2013.
This is three times as many accounts as previously estimated back in December 2016, in what was already the largest breach in history.
Yahoo, which is now part of Verizon Communications, revealed that every one of its accounts were affected in a post on its account security update page. However, it stressed that any stolen information did not include passwords in clear text, payment card data, or bank account information.
In a statement, Yahoo said took action to protect all accounts and forced all users who had not changed their passwords since the time of the theft to do so. Unencrypted security questions and answers were also invalidated so they couldn’t be used to access an account.
The hack has dealt a heavy financial blow to Yahoo and its executives. Former chief executive Marissa Mayer gave up her 2016 cash bonus following the incident, but received a $186 million (£142.2 million) payout on her way out of the company in June. Meanwhile, the company’s top lawyer, Ronald Bell, resigned in the wake of the hack and the other breaches.