A Silicon Valley-based security firm called Area1 says it has found indications that state-sponsored Russian hackers have successfully hacked the Ukranian gas company Burisma, as first reported by the The New York Times. The company has taken on a central role in US politics because of its connection to Democratic presidential front-runner Joe Biden, whose son Hunter sits on the company’s board.

In July, President Trump asked Ukraine’s government to investigate Burisma to find damaging information on the Biden family, allegedly threatening to withhold military aid to the country if the prime minister did not announce an investigation. That request is at the center of the president’s ongoing impeachment proceedings, and has made Burisma a tempting target for anyone seeking to meddle in US politics.

According to Area1, the security firm that detected the attacks, says they detected phishing emails sent to Burisma employees bearing many of the hallmarks of GRU hacking campaigns. The hackers were apparently successful in getting employee login info they used to gain entry into one of Burisma’s servers, although it is unclear how much information was obtained. If the GRU is in fact involved, it’s possible the group could have been looking for embarrassing information to be released during the 2020 presidential campaign.

In hacking Burisma, the Russian hackers could be following a similar playbook as what they reportedly did to undermine Hillary Clinton’s presidential campaign during the 2016 election. In January 2017, US intelligence officials released a report outlining how that Russian intelligence services successfully hacked the Democratic National Committee and stole information that was slowly and regularly leaked to the public to help the campaign of then-candidate Trump.