The U.S. Department of Justice announced Wednesday it charged 2 Russian intelligence agents and their accomplices for hacking into Yahoo mail and obtaining private information from millions of email accounts.

Yahoo reported the cyberattack in September of 2015, admitting that more than 500 million accounts were compromised in the act. The Justice Department released a statement naming the accused and describing the charges.

A grand jury in the Northern District of California has indicted four defendants, including two officers of the Russian Federal Security Service (FSB), for computer hacking, economic espionage and other criminal offenses in connection with a conspiracy, beginning in January 2014, to access Yahoo’s network and the contents of webmail accounts. The defendants are Dmitry Aleksandrovich Dokuchaev, 33, a Russian national and resident; Igor Anatolyevich Sushchin, 43, a Russian national and resident; Alexsey Alexseyevich Belan, aka “Magg,” 29, a Russian national and resident; and Karim Baratov, aka “Kay,” “Karim Taloverov” and “Karim Akehmet Tokbergenov,” 22, a Canadian and Kazakh national and a resident of Canada.

The statement alleges that the hackers used the information to gain unauthorized access to accounts at Yahoo and elsewhere, targeting "Russian journalists, U.S. and Russian government officials and private-sector employees of financial, transportation and other companies." Gift cards and credit card numbers were also sought via the email accounts to enrich one of the defendants.

The statement alleges that the conspiracy began as early as 2014 and continued into December of 2016.

FBI Special Agent Jack Bennet spoke to the press about the charges Monday.

"We want to send a clear message to criminal hackers everywhere - you can try to hide in the corners of the dark web, but we will hunt you down, we will expose you, and we will bring you to justice."

These were two FSB officers, using FSB infrastructure, and FSB tools and techniques. This was a nation state, yes they use criminal hackers on here. These are people that have all the time in the world and every day they keep banging on systems and eventually they will find a crack. We didn't know what we had and neither did Yahoo until we got deeper into this. And I know that was one of the criticisms, until there were deeper investigations as to how deep and how far this went, it wasn't appropriate for anybody to comment on it, because we just didn't know.

"These are sophisticated," Bennet added, "very complex investigations. This is not just going in and grabbing a hard drive and doing a forensic dive on it. These are network data flows and information we have to go back and determine what we need. "

Bennet explained that while there is no extradition treaty with Russia, they expect that the hackers charged will one day attempt to visit other countries that may have extradition treaties, and the Justice Department will "take advantage of that."

The Trump administration has been fighting back accusations that there were unlawful interactions and ties with the Russian government before the election, saying that there is no evidence supporting the allegations. Democrats and other detractors have cited leaks from the administration to substantiate the claims, while President Trump has blamed the media and his allies accused the "deep state" of anti-Trump bureacrats of attempting to sabotage his presidency.