The top leaders in Congress have known for a year that the Democratic Party was under attack by Russian hackers, Reuters reported on Friday.

Citing three sources familiar with the matter, the news agency said U.S. intelligence officials gave the top leaders in Congress and the ranking members of the intelligence committees from both parties in the House and Senate a top secret briefing that “U.S. spy agencies had concluded that two Russian intelligence agencies or their proxies were targeting the Democratic National Committee, the central organizing body of the Democratic Party.”

The officials included then–House Speaker John Boehner, House Minority Leader Nancy Pelosi, Senate Majority Leader Mitch McConnell, Democratic Minority Leader Harry Reid, ranking Senate Intelligence Committee members Sens. Richard Burr and Dianne Feinstein, and ranking House Permanent Select Committee on Intelligence members Reps. Devin Nunes and Adam Schiff.

The officials were not allowed to disclose information about the hack because U.S. intelligence officials were monitoring the hacking using sources and methods they wanted to remain secret.

The new report would seem to confirm what experts have suspected since WikiLeaks published tens of thousands of hacked emails from the Democratic National Committee last month on the eve of the party’s convention: That the Russians were behind the attack.

On Wednesday, the New York Times reported that the scope of the attack was wider than believed, with the perpetrators having gained access to the private email accounts of as many as 100 Democratic Party officials and groups, including officials in the Hillary Clinton campaign. Reuters reported that the Democratic Congressional Campaign Committee, which is the fundraising arm for House Democrats, was also successfully targeted. Citing its own sources, CNN confirmed aspects of that Times report on Thursday, including the hacking of officials with direct ties to the Clinton campaign. Former House Speaker Pelosi called the hacking an “electronic Watergate” on Thursday and publicly attributed the attack to Russia.

The Clinton campaign has repeatedly speculated that the Russians are using the hack to meddle in the presidential election with the hopes of damaging the Democratic nominee and boosting Donald Trump, who has made positive statements about Russian strongman Vladimir Putin and whose campaign manager Paul Manafort has extensive ties in Russia, which were reported in May by Slate’s Frank Foer.

Last month, Yahoo News reported that Democratic National Committee consultant Alexandra Chalupa was informed that Yahoo suspected her personal account had been targeted by “state-sponsored actors.” This came one week after she had begun to prepare opposition research on Manafort for the DNC.

Yahoo also reported at the time that two sources said that the hack included potentially embarrassing personal information about major donors to the Democratic Party, including “vetting” evaluations of those contributors.

The DNC was only made aware by the FBI last fall that their security might have been at risk, Reuters reported, months after the top secret congressional briefing. Clinton’s campaign, meanwhile, learned of a possible breach in March and was only given a “general” FBI briefing on the topic a month later.

What this all means is what has already been suspected since last month: That Russia is likely using WikiLeaks to disseminate hacked information about the Democratic Party in a direct attempt to influence the United States’ electoral process on behalf of Donald Trump. WikiLeaks founder Julian Assange has promised more revelations in the lead-up to November’s election.

Schiff, the ranking Democrat on the Permanent Select Committee on Intelligence, may have put it best when he said this on Thursday:

If this indeed turns out to be a cyberattack and leak conducted by a foreign actor to influence our elections, that would be a grave matter that should come with serious consequences. That foreign actors may be trying to influence our election—let alone a powerful adversary—should concern all Americans of any party.

Read more Slate coverage of the 2016 campaign.