Russia has been interfering with the work of FBI via hacking its networks - so as to prevent the Bureau from tracking Russian spies in the States. Business Insider came up with a story, telling about the U.S. findings in this regard.
"The investigation found that Russia's hack of the FBI's communication systems was a key reason the Obama administration kicked out 35 Russian diplomats and closed two Russian diplomatic facilities in December 2016. President Barack Obama said the measures were in retaliation for Russia's interference in the 2016 election, but Yahoo News reported that the US also wanted to close those two compounds because they were critical to Russia's efforts to intercept FBI communications", reads the story.
The Russians first breached the FBI's communication systems in 2010, after the arrest and exposure of a group of Russian spies in the US, Yahoo News said. That year, the FBI began investigating Russia's efforts to recruit US assets; one of the foremost targets was Carter Page, who later served as a foreign-policy aide on President Donald Trump's campaign.
The FBI informed Page in 2013 that the Russians were trying to cultivate him, but Page ignored their warnings and even publicly boasted about his connections to high-ranking Russian government officials.