The US government is terrified that all its hacking off of Iran over the years could result in its power grid being hacked.

The FBI has warned US.businesses to be on the alert for a sophisticated Iranian hacking operation whose targets include defence contractors, energy firms and educational institutions.

Cyber security firm Cylance last week warned about something similar. It thought the Iranians were targeting critical infrastructure organizations worldwide. Cylance has said it uncovered more than 50 victims from what it dubbed Operation Cleaver, in 16 countries, including the United States.

The FBI's confidential "Flash" report provides technical details about malicious software and techniques used in the attacks, along with advice on thwarting the hackers.

Cylance Chief Executive Stuart McClure said the FBI warning suggested that the Iranian hacking campaign may have been larger than its own research revealed. "It underscores Iran's determination and fixation on large-scale compromise of critical infrastructure," he said.

Hackers typically launch their attacks from two IP addresses that are in Iran, but did not attribute the attacks to the Tehran government. Cylance has said it believes Iran's government is behind the campaign which Iran has vehemently denied.

Of course, if ISIS wanted to get America to attack Iran, it would be easy to base its cyber attacks in that country. Right now, the Iranians and the Americans are semi-united in their hatred of ISIS.