It seems that the Russians are not done meddling in US politics. According to reporting by Reuters, Russian military hackers tried to steal emails from Burisma Holdings, the Ukrainian energy firm that is at the center of President Trump’s controversial impeachment trial.

Burisma was at the center of attempts by President Donald Trump last July to pressure Ukrainian authorities into announcing an investigation into Joe Biden and his son, Hunter, who served on the Board of Burisma. It was that effort that has led to Trump being only the third president in history to be impeached by the U.S. House of Representatives on charges of abuse of power and obstruction of Congress.

Trump denies he did anything wrong by asking Ukrainian officials to investigate Hunter Biden’s relationship with Burisma. Of course the Bidens reject Trump’s allegations of graft and corruption.

According to Reuters, California-based Area 1 Security identified the hacking of Burisma and linked it to Russia’s Main Directorate of Military Intelligence, or GRU. The same hacking group, known as “Fancy Bear” or “APT28” by cybersecurity researchers, breached the Democratic National Committee in 2016 in what U.S. investigators described as part of an operation to disrupt that year’s election.

“You can see this attack really is starting to parallel with what we saw in 2016,” Oren Falkowitz, Area 1’s chief executive, said in an interview.

The Russian Defense Ministry did not immediately respond to a request for comment. Officials at the U.S. National Security Agency and the Department of Homeland Security declined to comment.

Burisma did not immediately respond to a request for comment. However, a source close to Burisma told Reuters the company’s website had been subject to multiple break-in attempts over the past six months but did not provide further details.

What data the hackers were looking to steal, is not clear, Area 1 said. Breaching Burisma could yield communications from, to, or about Hunter Biden, who served as a director between 2014 and 2019. A leak of stolen data could potentially affect the impeachment process and the 2020 U.S. presidential election, much as the Russian hack of the DNC and release of obtained emails may have done in 2016.

Area 1’s report said it discovered the GRU had targeted two subsidiaries of Burisma – KUB Gas LLC and Esko Pivnich – as well as CUB Energy Inc, which previously did business with the company, using lookalike domains intended to trick employees into providing their email passwords.

Burisma and its subsidiaries share the same email server, Area 1 said, meaning a breach at any of the companies could expose them all.