WASHINGTON, United States (AFP) — Two Russian intelligence agents and a duo of hackers were indicted Wednesday over a data breach that compromised 500 million Yahoo accounts in one of the largest cyberattacks in history.

The indictment announced by the US Justice Department links Russia’s top spy agency, the FSB, to the massive hacking operation, which began in 2014 with the twin goals of espionage and financial gain.

It comes amid a high-stakes investigation into Russian cyber-meddling in the US election, potentially aimed at boosting the campaign of President Donald Trump.

The Russian agents were identified as Dmitry Dokuchaev and Igor Sushchin, both members of the successor agency to Russia’s KGB.

Dokuchaev was an officer in the FSB Center for Information Security, known as “Center 18,” which is tasked with investigating hacking and is the FBI’s point of contact in Moscow for cyber crimes.

The 33-year-old Dokuchaev was reported to have been arrested in Moscow earlier this year on treason charges. He is accused of directing the Yahoo hack along with his superior, the 43-year-old Sushchin.

The two officers “protected, directed, facilitated and paid criminal hackers to collect information through computer intrusions in the United States and elsewhere,” acting assistant attorney general Mary McCord told reporters. 

They are accused of hiring hackers Alexsey Belan and Karim Baratov to carry out the attacks, which continued until late 2016.

Targets of the Yahoo breach included both Russian and US government officials, including cyber security, diplomatic and military personnel, according to McCord, who said it aimed to gather information “clearly some of which has intelligence value.”

She added that “the criminal hackers used this to line their own pockets for private financial gain,” seeking to cash in on the breach by accessing stolen credit or gift card numbers, and through a series of spam marketing schemes.

The US indictment includes 47 criminal charges including conspiracy, computer fraud, economic espionage, theft of trade secrets and identity theft.

Asked if there were any links between the Yahoo hack and the wider question of Russian interference, McCord said, “We don’t have anything that suggests… any relationship,” but added that the election case “is an ongoing investigation.”

The US statement said some targets were “of predictable interest” to the Russian spy agency including Russian and US government officials and employees of a prominent Russian cybersecurity company.

The Yahoo breach, McCord said, “also targeted Russian journalists; numerous employees of other providers whose networks the conspirators sought to exploit; and employees of financial services and other commercial entities.”

Other accounts compromised by the hackers belonged to employees of commercial entities, such as a Russian investment banking firm, a French transportation company, US financial services and private equity firms, a Swiss bitcoin wallet and banking firm and a US airline, according to the Justice Department.

Baratov, a 22-year-old Canadian-Kazakh national, was arrested this week on a US warrant in Canada, she said. 

Belan, 29, has been indicted twice in US cases involving the hacking of e-commerce companies, and is listed as one of the FBI’s “Cyber Most Wanted criminals.”