From The Guardian (UK):

The UK government was given details last December of allegedly extensive contacts between the Trump campaign and Moscow, according to court papers.

…

The December memo alleged that four Trump representatives travelled to Prague in August or September in 2016 for “secret discussions with Kremlin representatives and associated operators/hackers”, about how to pay hackers secretly for penetrating Democratic party computer systems and “contingency plans for covering up operations”.

Between March and September, the December memo alleges, the hackers used botnets and porn traffic to transmit viruses, plant bugs and steal data online from Democratic party leadership. Two of the hackers had been “recruited under duress by the FSB” the memo said. The hackers were paid by the Trump organisation, but were under the control of Vladimir Putin’s presidential administration.