CISA has documented a dangerous attack that was caught quickly by a vigilant operator at the Florida plant to prevent impacts in the attempt to poison the major water supply

Compromise of U.S. Water Treatment Facility | CISA

Compromise of U.S. Water Treatment Facility | CISA

Lye-poisoning attack in Florida shows cybersecurity gaps in water systems (nbcnews.com)

On February 5, 2021, unidentified cyber actors obtained unauthorized access to the supervisory control and data acquisition (SCADA) system at a U.S. drinking water treatment plant. The unidentified actors used the SCADA system’s software to increase the amount of sodium hydroxide, also known as lye, a caustic chemical, as part of the water treatment process. Water treatment plant personnel immediately noticed the change in dosing amounts and corrected the issue before the SCADA system’s software detected the manipulation and alarmed due to the unauthorized change. As a result, the water treatment process remained unaffected and continued to operate as normal. The cyber actors likely accessed the system by exploiting cybersecurity weaknesses, including poor password security, and an outdated operating system. Early information indicates it is possible that a desktop sharing software, such as TeamViewer, may have been used to gain unauthorized access to the system. Onsite response to the incident included Pinellas County Sheriff Office (PCSO), U.S. Secret Service (USSS), and the Federal Bureau of Investigation (FBI).