U.S. Department of Homeland Security investigations of cyber attacks on the nation's critical manufacturing sector nearly doubled in the year ended Sept. 30, according to the agency.
The Department of Homeland Security's Industrial Control Systems Cybersecurity Emergency Response Team, or ICS-CERT, said in a report distributed this week that it investigated 97 incidents at critical manufacturers during its most-recent fiscal year.
That category includes makers of vehicles and other types of transportation equipment as well as metals, machinery and electrical equipment producers.
ICS-CERT said that altogether it responded to a total of 295 cyber incidents, up 20 percent from the previous fiscal year.
After critical manufacturing, the next most active sectors were energy, with 46 incidents, water, with 25, and transportation systems, with 23, according to the report. (1.usa.gov/1lepgB4)
The document did not say whether any of the incidents caused outages or say who was behind them. A DHS spokesman declined to elaborate.
Cyber experts say that such incidents could be caused by unintentional infections of criminal malware, nations and criminals gathering data to prepare for potential destructive attacks in the future, or attacks looking to disrupt service.
The annual data provides a rare glimpse into investigations by ICS-CERT, a body that helps critical infrastructure operators defend against cyber attacks. ICS-CERT provides more detailed data on cyber incidents through private channels including a secure web portal.
ICS-CERT released the data after the agency's chief, Marty Edwards, on Wednesday warned of an increase in attacks that he said were caused by operators exposing industrial control systems to the Internet.
“I am very dismayed at the accessibility of some of these networks... They are just hanging right off the tubes," he said at the S4 security conference in Miami.
He did not provide statistics detailing the extent of the increase.
Industrial control systems are computer systems that run industrial processes at facilities ranging from energy plants and steel mills to water systems and breweries.
(Reporting by Jim Finkle; Editing by Alistair Bell)