Someone supposedly dropped off a laptop for repair - at a shop that just happens to be owned by one of Rudy's guys. And they found PDFs on it - that were created after it was dropped off, but no matter - implicating Hunter.
This is what happens when old guys try to commit computer fraud.
Link: https://www.thedailybeast.com/trump-knew-for-weeks-that-rudy-giulianis-hit-on-hunter-biden-was-coming