Yahoo is expected to confirm a data breach that exposed hundreds of millions of credentials dating back four years. A report published today by Recode intimates that the total number of exposed credentials will be higher than the 200 million initially reported in early August. The breach would be among the largest credential leaks this year, which has already been littered by a number of high-profile, high-volume exposures of passwords and personal account information. The greater security issue hanging over the Yahoo leak and all the others this year is password reuse.
Source: https://threatpost.com/yahoo-reportedly-to-confirm-breach-of-hundreds-of-millions-of-credentials/120797/