Iran has launched huge cyberattacks against the US, just hours before Donald Trump's deadline for Tehran to reopen the Strait of Hormuz ends or face complete destruction. The US Cybersecurity and Infrastructure Security Agency warned that actors affiliated with Tehran have been "conducting exploitation activity" targeting certain devices.

It said the hackers disrupted critical infrastructure sectors and caused financial losses via "malicious interactions", and urged US organisations to urgently review their networks "to reduce the risk of compromise". The agency previously reported similar activity by CyberAv3ngers - a group affiliated with the Islamic Revolutionary Guard Corps (IRGC) Cyber Electronic Command (CEC).

The agency said: "Iran-affiliated advanced persistent threat (APT) actors are conducting exploitation activity targeting internet-facing operational technology (OT) devices, including programmable logic controllers (PLCs) manufactured by Rockwell Automation/Allen-Bradley.

"This activity has led to PLC disruptions across several US critical infrastructure sectors through malicious interactions with the project file and manipulation of data on human machine interface (HMI) and supervisory control and data acquisition (SCADA) displays, resulting in operational disruption and financial loss.

"US organizations should urgently review the tactics, techniques, and procedures (TTPs) and indicators of compromise (IOCs) in this advisory for indications of current or historical activity on their networks, and apply the recommendations listed in the Mitigations section of this advisory to reduce the risk of compromise."

This comes after the US President warned a "whole civilisation" could "die tonight" should Iran not comply with his demand to reopen the Strait of Hormuz.

Taking to Truth Social on Tuesday afternoon, just hours away from the deadline he set over the Easter holidays, he seemingly threatened Iran with utter devastation.

He wrote on the social media platform: "A whole civilization will die tonight, never to be brought back again. I don’t want that to happen, but it probably will.

"However, now that we have Complete and Total Regime Change, where different, smarter, and less radicalized minds prevail, maybe something revolutionarily wonderful can happen, WHO KNOWS?

"We will find out tonight, one of the most important moments in the long and complex history of the World. 47 years of extortion, corruption, and death, will finally end. God Bless the Great People of Iran!"