The whole DNC-hack-by-Russia narrative was concocted by Crowdstrike to support this story. They had been brought in to investigate the Podesta email phishing episode and had found common malware on the servers that they “speculated” had been left by “Russian” actors although this was never proved. From their secret House testimony they never found any evidence that emails had been “extirpated” out of the DNC servers but they publicly claimed this was how the DNC emails made it to Wikileaks to close the Russia hack loop. The Russian hacking hoax was thus born.
Somehwere around that timeframe there was news that the CIA had some program or whatever that could make it look as thought actor A, B, or C hacked, when it was really the CIA>
But in this case it was Seth Rich downloading onto a thumbdrive. THe time take to download that ways is much less than a hacker onver the internet.