When Roger Caslow, CISO of the Hampton Roads Sanitation District, realized his organization was under a ransomware attack, he gave the order.

"I immediately told my engineers: 'Go downstairs and disconnect everything,'" Caslow says. "This is a hard disconnect. Everything is hard - pull plugs, pull plugs, pull plugs."

The district, which serves 1.7 million people in eastern Virginia, was infected with the Ryuk ransomware in November 2020. Fortunately, its operational technology systems were unaffected due to proper segregation between that and its information technology environment.

But the attack took out many of its Windows computers, hampering its email, billing systems and more. HRSD is just one of several water and wastewater facilities that have been hit by ransomware over the past two years.