A U.S. cybersecurity company says Russian military agents successfully hacked the Ukrainian gas company at the center of the scandal that led to President Donald Trump’s impeachment. Russian agents launched a phishing campaign in early November aimed at stealing login credentials for employees of the gas company, Burisma Holdings. That’s according to Area 1 Security, a Silicon Valley specialist in email security. It isn’t clear what the hackers were looking for or may have obtained. The operation’s timing suggests that Russian agents may have been searching for material that could damage former U.S. Vice President Joe Biden. Biden’s son Hunter used to serve on Burisma’s board.