The US government is expected to unseal charges against two Russian spies and two criminal hackers for allegedly pilfering 500 million Yahoo user accounts in 2014, a source familiar with the matter says.
The indictments, to be unsealed during a news conference in Washington on Wednesday, represent the first time the US government has criminally charged Russian officials for cyber offences.
According to the source, they are not related to the hacking of Democratic emails that took place during the 2016 US presidential election. Intelligence agencies have said they were carried out by Russia in order to help the campaign of Republican President Donald Trump.
Two Russian spies and two criminal hackers will be charged in the 2014 Yahoo attack, the Washington Post earlier reported, citing unnamed officials. The officers of the FSB, Russia's Federal Security Service and a successor to the KGB, were identified as Dmitry Dokuchaev and his superior, Igor Sushchin, according to the paper.
Alexsey Belan, who is on the list of most-wanted cyber criminals, and Karim Baratov, who was born in Kazakhstan but has Canadian citizenship, were also to be named in the indictment, the Post reported.
Yahoo said, when it announced the then-unprecedented breach last September, that it was working with law enforcement authorities and believed the attack was state-sponsored.
The company announced a still-larger breach in December that occurred in 2013 and affected one billion accounts, though it has not linked that intrusion to the one in 2014.
The breach announcements were the latest in a series of setbacks for the Internet pioneer, which has fallen on hard times in recent years after being eclipsed by younger, fast-growing rivals.
Yahoo's disclosure of the years-old cyber invasions and its much-criticised slow response forced it to accept a discount of US$350 million (NZ$503 million) in what had been a $US4.83 billion (NZ$6.9b) deal to sell its main assets to Verizon Communications.