Russian hackers have targeted Burisma Holdings, the gas company which 2020 presidential candidate Joe Biden‘s son, Hunter Biden, previously had a board sear, as the Senate impeachment trial continues to revolve around the President Donald Trump’s alleged effort to manipulate the Ukrainian president into launching an investigation into the Biden family.

A cybersecurity firm revealed last week that it discovered the covert computer attacks that the Russian hackers targeted on Burisma Holdings. According to the research firm Area 1 Security released on Monday, the Russian hackers, who are believed to be affiliated with Russian military special operations, conducted a cyberattack on Burisma Holdings back in November 2019.

The alleged attack took place when witnesses were being questioned in the Congressional impeachment proceedings. Congress had been attempting to determine whether Trump had abused his power in office by trying to manipulate Zelensky into investigating Biden by blocking $391 million of military assistance to the country.

Area 1 alleges that the covert operation parallels the 2016 Democratic election hack, in which the DNC server had been compromised. Hilary Clintons campaign email accounts were compromised, along with other sensitive information and data that had been leaked back in 2016.

Area 1 claimed that the attack involved the GRU, the same group of the Russian military which had been responsible for the 2016 Democratic election server hack.

“Our report is not noteworthy because we identify the GRU launching a phishing campaign, nor is the targeting of a Ukrainian company particularly novel. It is significant because Burisma Holdings is [publicly] entangled in U.S. foreign and domestic politics,” the Area 1 report states.

“The timing of the GRU’s campaign in relation to the 2020 U.S. elections raises the spectre that this is an early warning of what we have anticipated since the successful cyberattacks undertaken during the 2016 U.S. elections,” the firm added.

Biden’s electoral team seized on the news on Monday.

“This proves that both Donald Trump and Vladimir Putin understand the true stakes of this election,” Andrew Bates, spokesperson for Biden for President, said in a statement. “Donald Trump tried to coerce Ukraine into lying about Joe Biden and a major bipartisan, international anti-corruption victory because he recognized that he can’t beat the Vice President. Now we know that Vladimir Putin also sees Joe Biden as a threat.”