Two officers with Russia's intelligence service, the FSB, are among four people facing charges in a massive Yahoo hacking attack, in which they are accused of stealing the personal information of hundreds of millions of users.

The defendants are three Russian nationals and residents, and one Canadian and Kazakh national who lives in Canada, the Department of Justice said.

The breach affected at least 500 million Yahoo accounts, the Department of Justice said. The hackers are accused of accessing personal accounts belonging to those including Russian journalists, Russian government officials, U.S. government officials, U.S. financial services and private equity firms and a U.S. airline, the Justice Department said.

The DOJ announced the charges this morning, calling the Yahoo hacks one of the largest data breaches in history.

The Justice Department said, "FSB officer defendants, Dmitry Dokuchaev and Igor Sushchin, protected, directed, facilitated and paid criminal hackers to collect information through computer intrusions in the U.S. and elsewhere. ... They worked with co-defendants Alexsey Belan and Karim Baratov to obtain access to the email accounts."

Belan was named one of the FBI’s Cyber Most Wanted criminals in November 2013.

The alleged crime began at least as early as 2014. The defendants lost access to Yahoo’s networks in September 2016 but continued to use stolen information stolen until at least December 2016, according to the DOJ.

"The criminal conduct at issue, carried out and otherwise facilitated by officers from an FSB unit that serves as the FBI’s point of contact in Moscow on cybercrime matters, is beyond the pale," Acting Assistant Attorney General McCord said in a statement.

“Once again, the Department and the FBI have demonstrated that hackers around the world can and will be exposed and held accountable. State actors may be using common criminals to access the data they want, but the indictment shows that our companies do not have to stand alone against this threat."

This story is developing. Please check back for more updates.