The data of 200 million Yahoo users is for sale on the Dark Web, according to a report by Softpedia.
The report stated that the listing has been published on the TheRealDeal Dark Web marketplace.
Yahoo said it is investigating the breach, which was put up for sale by hacker Peace_of_Mind.
Peace_of_Mind has previously sold data from sites such as LinkedIn, MySpace, Tumblr, Fling.com, and VK.com, said Softpedia.
The hacker said the Yahoo data for sale is from 2012.