Iranian hacking group that it calls Advanced Persistent Threat 33 (or APT33) targeted aerospace, defence and energy organisations in the United States, Saudi Arabia and South Korea. The group has been targeting critical infrastructure, energy and military sectors since at least 2013 as part of a massive cyber-espionage operation to gather intelligence and steal trade secrets. FireEye researchers have spotted cyber attacks aimed by the group since May 2016 and found that the group has successfully targeted aviation sector as well as energy sector with a link to petrochemical.
Source: https://thehackernews.com/2017/09/apt33-iranian-hackers.html