New York CNN  — 

Some US officials are now bracing for Iran to retaliate against the US with a cyber attack in response to the killing of one of its top commanders. But Iran has shown it’s also capable of engaging in another form of online warfare: social media disinformation campaigns.

Americans may associate this tactic more with Russia, but Iran has turned to this playbook too. While a conventional cyber attack could potentially shut down a hospital or compromise a power grid, disinformation campaigns have the potential to sow discord and influence the American electorate.

In recent years, Facebook and Twitter have found people and organizations believed to be linked to the Iranian government operating thousands of covert social media accounts combined between the two platforms posing as regular users and independent organizations, including news outlets.

The accounts commonly shared stories portraying the Iranian regime in a positive light while attacking Tehran’s enemies.

“Iran has readily embraced the use of online information operations to support its geopolitical objectives over the past few years, and has refined a vast array of tactics and sophisticated methods that it continues to hone and leverage today,” Lee Foster, a senior manager on the information operations analysis team at cyber security company FireEye, told CNN Business on Friday.

The Pentagon confirmed Thursday that a drone strike ordered by President Donald Trump killed Qasem Soleimani, the head of the Islamic Revolutionary Guards Corps (IRGC) Quds Force, escalating tensions between the US and Iran. Secretary of State Mike Pompeo told CNN the Trump administration anticipates “a wide range of possible responses.”

Foster, whose team has closely studied Iranian disinformation campaigns, said among the disinformation tactics they’ve seen used by Iran is the “creation of networks of inauthentic social media accounts masquerading as real, politically-inclined individuals, including those based in the US.” Those accounts, he said, often spread “commentary critical of Iran’s political rivals.”

And it’s not just on social media. In one case, a pro-Iranian influence campaign even succeeded in having letters to the editor published in American newspapers at least 13 times, according to FireEye. While the letter writing campaign was not tied directly to the Iranian government, Facebook, which examined accounts and personas associated with FireEye’s findings, confirmed they were operated from inside Iran.

One of the letters published by two major American newspapers argued that the best way to honor the memory of Jamal Khashoggi, a Saudi Arabian dissident killed by his government, would be if the US stopped backing Saudi Arabia’s role in the civil war in Yemen. Withdrawing from Yemen in this way would align with Tehran’s interests.

In the run-up to the 2016 US presidential election, Russia waged a disinformation campaign targeting American voters — posing as American activists from across the political spectrum. Those accounts sought to sow discord within the United States, and rarely made mention of Russia.

Graham Brookie, director of the Atlantic Council’s Digital Forensic Research Lab, told CNN Business that Iranian online campaigns are different. Although they may use covert personas, he said, “nearly all content spread by Iran’s digital influence efforts relates directly to its worldview or specific foreign policy objectives. Iran attempts to present and persuade to a side, as opposed to engage and infiltrate to cause chaos on all sides.”

Both Brookie and Foster note, however, that accounts run from Iran have sought to exacerbate division in the US in a way that still aligns with Iran’s interests.

In October 2018, Facebook took down a network of accounts run from Iran targeting people in the US and the United Kingdom. The company said at the time it was not able to determine if the accounts were tied to the Iranian government.

Some of the Facebook pages were named “Wake Up America,” “No racism no war,” and “Thirst for Truth,” and memes posted by the pages included one about President Trump that called him, “The worst, most hated president in American history!”