The FBI's cyber division on Tuesday said hackers linked to Iran's ruling regime are attacking devices connected to critical US infrastructure.
The warning comes after Handala, an Iran-linked cyber crime group, hacked and obtained emails, photos and other correspondence from FBI Director Kash Patel.
It also comes weeks after Iran-linked hackers struck computers and smartphones of employees at Michigan medical technology company Stryker.
The FBI detailed some of the recent hacks against US infrastructure so far, including industrial computers known as programmable logic controllers.
“These attacks have led to diminished PLC functionality, manipulation of display data and, in some cases, operational disruption and financial loss,” the FBI's cyber division said on X.
The FBI said hackers had aimed for devices across critical US systems, including those related to water and wastewater, and energy. The document said many of the attacks took place in March.
The FBI suggested ways to mitigate the possible effects of the hacks, which include disconnecting PLCs “from the public-facing internet".
Months before the Iran war began on February 28, Brett Leatherman, who leads the FBI’s cyber operations division, had warned that the US was seeing an increase in cyber crime activity from Iran.
During an August appearance at George Washington University’s Programme on Extremism, Mr Leatherman spoke about what Iran should expect if it goes for critical US digital infrastructure.
“There’s a sense of mutually assured destruction, and if they hit us they now we can hit them back and can hit them back a lot harder,” he said.
“If you use cyber weapons to destroy infrastructure, you’re now destroying information that a sovereign nation depends on. That tends to be a red line.”
