Yahoo! Data Breach May Be Bigger Than First Reported

That hack at Yahoo!  (YHOO) could be much bigger than the online search engine first admitted. That's according to a former company executive with knowledge of its security practices tells Business Insider that the data breach in 2014 may have affected one billion users, that's twice what Yahoo quoted last week. The former Yahoo insider, who claims to be in contact with those leading the investigation internally, says all of Yahoo's products like Mail, Finance or Sports, use one main database to authenticate users. There were credentials of as many as one billion active users in 2014 in that database. The former employee tells Business Insider "I believe it to be bigger than what's being reported. How they came up with 500 is a mystery."

This article was written by a staff member of TheStreet.