https://www.theregister.co.uk/2017/10/03/yahoo_says_one_beeelion_user_hack_figure_wrong_its_three/

With Equifax testifying in US Congress today about its own massive security failings, someone at Yahoo! presumably thought now would be a good time to bury bad news – but some things are too large to hide.

In a filing on Tuesday to America's financial watchdogs, Yahoo!, now owned by Verizon under the Oath brand, admitted the total number of user accounts accessed by hackers in 2013 wasn't the 500 million earlier reported, nor the one billion it later reported, but all of them – all three billion accounts.