U.S. cybersecurity and social media companies investigated, identified and removed hundreds of social media accounts that originated in Iran in what Facebook called “coordinated inauthentic behavior,” meaning the accounts purposely misled followers over who they were and what they were doing.

The accounts were linked to an Iranian-backed propaganda platform called International Union of Virtual Media, created to spread false news to over half a million people a month in more than a dozen languages.

Facebook said on January 31 that roughly 2 million accounts followed at least one of the misleading pages. Twitter, too, has suspended hundreds of accounts “for engaging in coordinated manipulation” and said it appeared many of the accounts originated from Iran.

Ben Nimmo, a cybersecurity expert at the Atlantic Council’s Digital Forensic Research Lab, one of the U.S. organizations involved in the investigation, called it “the largest website-based influence campaign we’ve seen so far, both in terms of the number of websites it includes and the range of languages.”

Posing as independent news agencies

U.S. cybersecurity firm FireEye first identified the disinformation campaign in the summer of 2018 and alerted U.S. companies, including Facebook, Twitter and Google.

FireEye reported in its security blog that the campaign promotes an Iranian political agenda that includes “anti-Saudi, anti-Israeli, and pro-Palestinian themes.”

Posing as independent news agencies and civil society organizations, the Iranian-based network circulates Iranian state media messages and other disinformation on social media and news websites. The network is designed to influence public opinion in countries located in the Middle East, Latin America, the U.K. and the U.S.

Nimmo said they are waiting to confirm who is running the network — the Iranian government itself or supporters of the regime.

“Whoever is behind the network seems to be trying to publish Iranian regime messages online, while making it look as if the content comes from independent voices,” said Nimmo.

Investigative journalists from Reuters News Agency also uncovered additional false sites linked to Iran.