The US carried out a secret cyber operation against Iran in the wake of September 14 attacks on Saudi Arabian oil facilities, which Washington and Riyadh blame on Tehran, US officials told Reuters.
The officials, who spoke on condition of anonymity, said the operation took place in September and took aim at Tehran’s ability to spread “propaganda.”
One official said the strike affected hardware, but did not provide further details.
It highlights how President Donald Trump’s administration is trying to counter what it sees as Iranian aggression without spiralling into wider conflict.
The strike appears more limited than other similar operations against Iran after the downing of an American drone in June and an alleged attack by Iran’s Revolutionary Guards on oil tankers in the Gulf in May.
The United States, Saudi Arabia, Britain, France and Germany publicly blamed the September attack on Iran, which denied involvement in the strike. The Iran-aligned Houthi militant group in Yemen claimed responsibility.
Publicly, the Pentagon responded by sending additional troops and equipment to bolster Saudi defences – the latest US deployment to the region.
“As a matter of policy and for operational security, we do not discuss cyberspace operations, intelligence, or planning,” said Pentagon spokeswoman Elissa Smith.
The impact of the attack, if any, could take months to determine, but cyber strikes are seen as a less-provocative option below the threshold of war.
“You do damage without killing people or blowing things up; it adds an option to the toolkit we didn’t have before and our willingness to use it is important,” said James Lewis, a cyber expert with the Washington-based Centre for Strategic and International Studies.
Lewis added it may not be possible to deter Iranian behaviour with conventional military strikes.
Tensions in the Gulf escalated since May 2018, when Trump withdrew from the 2015 Joint Comprehensive Plan of Action with Tehran that put limits on its nuclear programme in exchange for easing sanctions.
It is unclear whether there have been other US cyber-attacks since September.
Iran used similar tactics against the US. This month, a hacking group apparently linked to the Iranian government tried to infiltrate email accounts related Trump’s re-election campaign.
Over 30 days in August and September, the group, which Microsoft dubbed “Phosphorous,” made more than 2 700 attempts to identify consumer accounts, then attacked 241 of them.
Tehran is thought to be a major player in spreading disinformation.
Last year a Reuters investigation found more than 70 websites pushing Iranian propaganda to 15 countries, an operation cybersecurity experts, social media firms and journalists are now starting to uncover.
Tensions with Iran are high since the September attack. Tehran claimed an Iranian tanker was hit by rockets in the Red Sea last week and warned there would be consequences.
At a news conference, President Hassan Rouhani reiterated his country’s policy to the Trump administration, ruling out bilateral talks unless Washington returns to the nuclear deal and lifts US economic sanctions.