In August of 2016, WikiLeaks promoted the Seth Rich conspiracy theory -- the theory that the slain DNC staffer was responsible leaking Democratic emails -- by announcing a $20,000 reward for information that leads to Rich's killers.
As crazy as it sounds, the idea was that Rich was killed by someone connected to the DNC or the Clintons and Wikileaks implied as much by offering a reward for information leading to them.
In reality, the Mueller report makes it clear that Wikileaks founder Julian Assange had already been in close contact with Russian intelligence agents for months; agents who were his sources for the DNC emails, not Seth Rich.
From The Daily Beast:
As laid out by Mueller, Assange’s involvement in Russia’s election interference began with a June 14, 2016 direct message to WikiLeaks’ Twitter account from “DC Leaks,” one of the false fronts created by the Russians to launder their hacked material.
“You announced your organization was preparing to publish more Hillary's emails,” the message read, according to Mueller’s report. “We are ready to support you. We have some sensitive information too, in particular, her financial documents. Let's do it together. What do you think about publishing our info at the same moment? Thank you.”
A week later, WikiLeaks reached out to a second GRU persona, Guccifer 2.0, and pitched WikiLeaks as the best outlet for the hacked material. On July 14, 2016, GRU officers used a Guccifer 2.0 email address to send WikiLeaks an encrypted one-gigabyte file named “wk dnc link I .txt.gpg.” Assange confirmed receipt, and on July 22 he published 20,000 DNC emails stolen during the GRU’s breach.
Assange began communicating with the Russians in June, they passed the files to him in July, and Assange implied that Seth Rich was his source in August.
And that's all it took for Fox News and the wingnutosphere to embark on conspiracy feeding frenzy that still hasn't been entirely extinguished in 2019.
Seth Rich's family has been put through hell because of an actual conspiracy between Wikileaks, the Trump campaign, and Russian intelligence.