Infrastructure software experts say the Stuxnet worm that has disrupted many of Iran’s nuclear powerplants—and is designed to target industrial controls—escalates the data-systems protection battle. The malware is said to be the first “rootkit”-level virus coded to attack powerplants and industrial controls. “This provides a blueprint for how control systems can be exploited,” says Mark Weatherford, chief security officer for the North American Electric Reliability Corp. The NERC consortium has urged members to upgrade user policies and run system scans since researchers discovered the worm last summer. The malware is designed to target programmable logic controllers (PLCs), says Liam Omercu,
Arch dams, classically curved monoliths situated in narrow valleys, are not as common as other types of dams, such as embankment dams and gravity dams. ENR takes a look at some of the biggest arch dams in the world, both completed and under construction.