The US has conducted secret cyber-operation against Iran, Reuters reports. The operation followed the drone attacks against the Saudi Aramco oil refinery, which were attributed by the US and its allies to Iran while Iran denied the involvement. According to Reuters' sources, the cyber-attacks targeted Iranian 'propaganda' machinery, including physical hardware. The Pentagon declined to comment about its cyber operations. Commenting on the news, the Head of Iran's Civil Defense Organization said that the US repeatedly conducts cyber-attacks against Iran, and warned of the legality of such actions.