Minnesota water systems hit with cyberattack, state officials say

A coordinated cyberattack disrupted water and wastewater utilities in more than 30 Minnesota communities Sunday and Monday, the state's technology bureau announced Tuesday.

In Braham, a town of 1,700, the water plant went offline and officials asked residents to conserve before attributing the outage to a malicious cyberattack by unknown actors. Plymouth, a Minneapolis suburb of 80,000, disconnected affected equipment at two water towers and multiple lift stations. Officials in both said water quality was unaffected.

Minnesota IT Services worked with state agencies alongside CISA, the EPA and the FBI. Chief information security officer John Israel said the whole-of-government response prevented more serious impacts.

No one has been publicly blamed. Federal agencies last week urgently warned of Iranian hacking groups targeting internet-connected operational technology. This month's U.S. strikes near the Strait of Hormuz destroyed an Iranian water facility, cutting access for more than 20,000 people, and the group Hanzala then claimed it had breached water systems in several California cities as a warning to Washington.

U.S. water infrastructure remains thinly defended, with 150,000 to 170,000 systems, many small and rural. An EPA audit found more than 70% out of compliance with federally required risk assessments.