SAN FRANCISCO — In early 2016, Russian intelligence officers obtained a new pool of the virtual currency Bitcoin. They quickly put the digital money to work.

The Russian spies used some of the Bitcoins to pay for the registration of a website, dcleaks.com, where they would later post emails that had been stolen from Hillary Clinton’s presidential campaign. When the operatives needed a computer server to host the dcleaks site, they paid for that with Bitcoins as well.

The transactions were detailed in an indictment on Friday from the Justice Department, in which prosecutors accused 12 Russian operatives of interfering in the 2016 presidential campaign through a sophisticated hacking scheme.

The indictment provided one of the clearest illustrations to date of the inner workings of the Russian operation that carried out the hacking of the Democratic Party and other targets. It also showed how cryptocurrencies — and the anonymity they provide — have become both a tool and a challenge for intelligence agencies in the battles between nation states.