The attack crippled computers used to control rocket and missile launches.
The United States launched cyber attacks against Iranian missile control systems and a spy network this week after Tehran downed an American surveillance drone, US media reported on Saturday.
US President Donald Trump ordered a retaliatory military strike against Iran after the drone shootdown but then called it off, saying the response wouldn't be "proportionate" and instead pledged new sanctions on the country.
But after the drone's downing, Trump secretly authorized US Cyber Command to carry out a retaliatory cyber attack on Iran, The Washington Post reported.
The attack crippled computers used to control rocket and missile launches, according to the Post, which cited people familiar with the matter.
Yahoo cited two former intelligence officials as saying the US targeted a spying group responsible for tracking ships in the strategic Strait of Hormuz, where Washington has blamed Iran for two recent mine attacks on oil tankers.
The Post said the strikes, which caused no casualties, had been planned for weeks and were first proposed as a response to the tanker attacks.
US defense officials refused to confirm the reports.
"As a matter of policy and for operational security, we do not discuss cyberspace operations, intelligence or planning," Defense Department spokeswoman Heather Babb told AFP.
On a day trip scheduled after Iran shot down a US drone, Pompeo flew into the Red Sea city of Jeddah and met with King Salman at his palace.
President Donald Trump has blamed Iran for attacks on oil tankers near the strategic Strait of Hormuz, but he also held out hope that implicit US threats to use force will yield talks with the Islamic Republic as the Pentagon
US President Donald Trump approved military strikes on Friday against Iran in retaliation for the downing of an unmanned $130-million surveillance drone, but pulled back from launching the attacks, the New York Times said.
Summary: "Today marks a new chapter in our journey for the development of peaceful nuclear energy with the issuing of the operating licence for the first Barakah plant," His Highness Sheikh Mohamed Bin Zayed Al Nahyan, Crown Prince of Abu Dhabi and Deputy Supreme Commander of the UAE Armed Forces, said in a tweet
The UAE has led the way in setting plans for the future. The only issue is that the technology is changing very fast. We still have progress to make in terms of changing the mindset, especially among government agencies that refuse to share their data — even with other departments, said Dr Saeed Al Matrooshi, CEO and Secretary-General at the Ajman Executive Council.
She signed up for the Little League because she loved the American sport, only to be rejected because she was not a boy.