Colin Munro Wood was not shocked when he learned that federal investigators believed the new website he had been writing for was a facade for a Russian troll operation looking to sway Americans ahead of the November election.

It explained the strange emails and writing prompts he had been receiving from his mysterious editor, an individual who admitted he was not based in the United States but wanted to weigh in on the presidential race.

“I just felt things were odd,” Mr. Wood said. And when his editor made it clear he didn’t want him to criticize President Trump or support Joseph R. Biden Jr., the Democratic presidential nominee, he started to figure out “they had a different kind of agenda.”

Mr. Wood, a 50-year-old who lives in Binghamton, N.Y., and has been writing for various online publications for years, was one of dozens of American and British nationals who wrote for the site Peace Data. The authorities said on Tuesday that it was part of a covert operation run by the Kremlin-backed Internet Research Agency, which conducted extensive election meddling in 2016.