A US information attack on Iran´s Revolutionary Guards in June prevented merchant ships sailing in the Gulf, The New York Times reported on Thursday.
The operation destroyed a storage site that allowed the IRGC to choose its targets and the location of the attack, a senior US official told the newspaper.
The June 20 cyber-attack against IRGC intelligence comes in a tense atmosphere in the strategic Strait of Hormuz after attacks on merchant ships attributed to Tehran, which has denied it.
On the same day, the Revolutionary Guards announced the destruction of a US drone that violated Iranian airspace.
The White House considered the information attack as an appropriate response to the destruction of the drone.
US President Donald Trump announced that he had canceled last-minute strikes on Iran in order to avoid heavy casualties.
Iran has not yet reformed its communications systems and has not prepared the Pentagon´s target information, the newspaper quoted US officials as saying.
The attack also affected Tehran´s ability to launch covert operations.
No ship has been involved since, but Iran last month seized a British-flagged Swedish oil tanker in the Strait of Hormuz, through which one-third of the world´s oil is transported by sea.
In response, British authorities seized two weeks ago an Iranian oil tanker off the coast of Gibraltar.
