FBI Investigates Yahoo’s Billion-User Breach that Includes Feds' Info

The FBI is investigating the breach of 1 billion Yahoo user accounts, a White House spokesman confirmed Thursday.

“There was a previously reported breach that the FBI had previously indicated that they were investigating and they’re investigating this situation as well, so I’ll let them speak to what they have found over the course of that investigation thus far,” White House Press Secretary Josh Earnest said during a Thursday press briefing.

Yahoo announced Wednesday an unknown third-party access personal information for the billion users in 2013 in what the company says is a separate incident from the breach of 500 million accounts it divulged in September but happened in 2014.

Among the stolen information, which included names, passwords and security questions and answers, was the account information for 150,000 U.S. government and military employees, Bloomberg Technology reported. Those accounts provided official government email addresses from the White House, National Security Agency, FBI, CIA and other agencies as password recovery backups. 

Yahoo suggests the party behind the breach may state-sponsored, as it did with the September announcement, though some security experts think it's criminals. 

For the affected users, the company required users to change passwords and invalidated unencrypted security questions and answers. It also suggests using a Yahoo Account Key, which validates accounts through a mobile phone instead of using a password.

The latest disclosure may affect the company's sale of key web business to Verizon. The $4.8 billion deal was reached before Yahoo announced either breach. CNBC reported Yahoo's shares fell 5 percent Thursday.