LANSING, Mich. (AP) — Michigan officials say nine water systems in the state were targeted by cyberattacks, days after authorities in Minnesota reported similar incidents affecting more than 30 water and wastewater systems.
The Michigan Department of Environment, Great Lakes, and Energy said it received a federal cybersecurity alert Tuesday warning of attempts to interfere with operational technology used by water systems.
State officials said several Michigan communities later reported activity matching the federal warning.
“All systems continued to operate safely, issues were addressed by local operators, and there are no known impacts that posed a public health concern,” department spokesperson Dale George said.
The FBI is investigating the attacks but has not publicly identified who is responsible.
Last week, the FBI, the Cybersecurity and Infrastructure Security Agency and other federal partners warned that Iranian hackers have been targeting water and wastewater systems and other critical infrastructure in the United States. Officials have not said whether the recent attacks in Michigan and Minnesota have been linked to that activity.
In Minnesota, state officials said there were no active requests for residents to reduce water use as of Thursday. Most of the confirmed attacks involved technology used to remotely monitor and control water system equipment. Officials said an affected system does not necessarily mean water service was interrupted.
The city of Braham, Minnesota, temporarily asked residents Monday to limit water use after its water treatment plant went offline during what city officials described as a cyberattack. Officials said the incident did not affect water quality, and service was maintained using water stored in the city’s water tower.
Officials in Plymouth, Minnesota, also reported that communications supporting the city’s water infrastructure were restored Tuesday after a cyberattack.
Cybersecurity experts have warned that water treatment facilities and other critical infrastructure can be vulnerable to cyberattacks because many rely on older technology and have limited resources to strengthen security.
