Research firm Graphika says a shadowy group of operatives in Russia produced more than 2,500 pieces of false information across seven languages on 300 different social media platforms. In one example, a fabricated tweet appears as if U.S. Senator Marco Rubio is accusing British authorities of spying on President Donald Trump.

The obscure disinformation campaign had been operating virtually undetected, according to new report published on Tuesday by social media researchers, NPR wrote.

The operation, named "Secondary Infektion" by researchers, has sought to spread pro-Russian propaganda around the globe by sharing fake tweets from U.S. elected officials and conspiracy theories about the coronavirus. And it attempted to interfere in the 2016 presidential election. Researchers say it will likely try to spread falsehoods tied to the November election, too.

Ben Nimmo, director of investigations at Graphika, the research firm that conducted the study, said in an interview that the specific culprit within Russia remains elusive.

"We don't know whether it was run by the government, or associated with the government, or a group who wanted to support the government," Nimmo said. "But the overall tone and context makes it clear that this was an operation which was trying to support the Russian government and attack and undermine its critics."

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Security officials at Facebook first identified the campaign last May, and since then, the tech giant and other platforms have been working to block the campaign. But it is so decentralized that it is still operating, though researchers say since it was exposed, the group's activity has slowed.

It is the latest contribution in a growing body of research about how disinformation is created and spreads online, as social media platforms debate how best to control potentially damaging and harmful false content aimed at exploiting divisions and causing chaos around national crisis or elections.

Nimmo said one thing stands out about the Secondary Infektion campaign: It almost never worked.

Just about every fake story it tried to spread fizzled fast, indicating that the group was likely driven more by a quota than by online impact.

"Which is an important reminder: Yes, there is disinformation on the Internet, but just because it's false, doesn't mean it's going to go viral," Nimmo said.

Instead of focusing on a handful of popular platforms and building up a large following, Secondary Infektion took the opposite tack: creating so-called burner accounts, spreading one piece of false information on Twitter, Facebook, Reddit or some other social media network and then completely abandoning the accounts and never returning to them.

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The content focused mostly on discrediting Ukraine and bolstering Russia. Some posts attempted to link Hillary Clinton to murder or tried to disparage German Chancellor Angela Merkel as an alcoholic. The campaign also worked to spread other baseless rumors, like that the U.S. was attempting to stoke a revolution in Azerbaijan. The accounts also created forged documents purporting to be written by congressional committees and fake Twitter messages, including a fabricated tweet that appears as if U.S. Sen. Marco Rubio is accusing British authorities of spying on President Trump.

"Sometimes they wouldn't even spell the politician's name right," Nimmo said. "They didn't seem to be very good at creating viral content."

While attention often focuses on the tactics of major disinformation campaigns by the Kremlin-backed Internet Research Agency and the Russian military intelligence agency, Nimmo said Tuesday's study demonstrates that it is but one slice of the false and distorted content coming out of Russia.

"Those are two parts of the puzzle, but there's a whole other piece of the puzzle, which is just as a big and just as complex, and that is Secondary Infektion," Nimmo said.

"As we look ahead to the election, our report shows there's all sorts of malicious activity we need to look out for, including burner accounts and forged documents that tries to interfere with peoples' thinking," he said.