In an email to Motherboard, Yahoo said “we are aware of a claim,” but stopped short of denying the info was authentic:
We are committed to protecting the security of our users’ information and we take any such claim very seriously. Our security team is working to determine the facts. Yahoo works hard to keep our users safe, and we always encourage our users to create strong passwords, or give up passwords altogether by using Yahoo Account Key, and use different passwords for different platforms.
Motherboard claims the data includes birthdates, usernames, passwords and in some cases the back-up email used for the account.
Peace claims the data is from “2012 most likely,” and is asking 3 Bitcoins for the lot (roughly $1,800). Motherboard tested dozens of usernames on Yahoo and found most of them to be active, but email addresses often came up as defunct.