Special counsel John Durham’s Report disclosed that three separate investigations into the Clinton Foundation were opened by the FBI in January 2016. We now know what the FBI was investigating—at least a very big part of it. 

In April 2015, The New York Times published a story about the Clinton Foundation, a flow of cash donations, and a company called Uranium One. 

The article was titled "Cash Flowed to Clinton Foundation Amid Russian Uranium Deal” and it detailed how Uranium One was sold to Russian government-controlled interests, giving Russia effective control of one-fifth of all uranium production capacity in the United States in the process.