NEW YORK • Sometimes, an international offensive begins with a few shots that draw little notice.
So it was on June 8, last year, when Mr Melvin Redick of Harrisburg, Pennsylvania, a friendly-looking American with a backward-facing baseball cap and a young daughter, posted on Facebook a link to a brand new website.
"These guys show hidden truths about Hillary Clinton, George Soros and other leaders of the US," he wrote. "Visit #DCLeaks website. It's really interesting!"
Mr Redick turned out to be a remarkably elusive character. No Melvin Redick appears in Pennsylvania records, and his photos seem to have been borrowed from an unsuspecting Brazilian.
But this fictional concoction has earned a small spot in history: The Redick posts that morning were among the first public signs of an unprecedented foreign intervention in United States democracy.
The DCLeaks site had gone live a few days earlier, posting the first samples of material stolen from prominent Americans by Russian hackers that would reverberate throughout the presidential election campaign and into Mr Donald Trump's presidency.
The site's phoney promoters were in the vanguard of a cyber army of counterfeit Facebook and Twitter accounts, a legion of Russian-controlled impostors whose cyber operations are still being unravelled.
The Russian information attack on the election did not stop with the hacking and leaking of Democratic e-mails or the fire hose of stories - true, false and in between - that battered Mrs Clinton on Russian outlets such as RT and Sputnik.
Far less splashy, and far more difficult to trace, was Russia's experimentation on Facebook and Twitter, the US companies that essentially invented the tools of social media and, in this case, did not stop them from being turned into engines of deception and propaganda.
On Wednesday, Facebook officials disclosed that they had shut down several hundred accounts they believe were created by a Russian company linked to the Kremlin and were used to buy US$100,000 (S$136,000) in ads pushing divisive issues during and after the US election campaign.
On Twitter, as on Facebook, Russian fingerprints are on hundreds or thousands of fake accounts that regularly posted anti-Clinton messages. Many were automated Twitter accounts, called bots, that sometimes fired off identical messages seconds apart - and in the exact alphabetical order of their made-up names, according to the FireEye researchers.
On election day, for instance, they found that one group of Twitter bots had sent out the hashtag #WarAgainstDemocrats more than 1,700 times.
The Russian efforts were sometimes crude or off-key, with a trial-and-error feel, and many of the suspect posts were not widely shared. The fakery may have added only modestly to the din of genuine American voices in the pre-election melee, but it helped fuel a fire of anger and suspicion in an already polarised country.
Multiple US government agencies have investigated the Russian attack, though it remains unclear whether any agency is focused specifically on tracking foreign intervention in social media.
Both Facebook and Twitter say they are studying the 2016 experience and how to defend themselves against such meddling.
"We know we have to stay vigilant to keep ahead of people who try to misuse our platform," Mr Alex Stamos, Facebook's chief security officer, wrote on Wednesday in a post about the Russia-linked fake accounts and ads. "We believe in protecting the integrity of civic discourse."