US Water System May Be , Vulnerable to Cyberattack, by China, Russia and Iran.br CNBC reports that the United States br water system has been the target of a series br of cyberattacks over the past few years. .br In response, the Environmental Protection Agency br (EPA) has been forced to issue an alert warning br that 70 of water systems do not comply br with the Safe Drinking Water Act.br According to the EPA, some have “alarming br cybersecurity vulnerabilities,” including br unchanged default passwords and former br employees who retain access to vital systems.br In February, the FBI issued a warning to br Congress that Chinese hackers have embedded br themselves into the U.S. cyber infrastructure. .br Those hackers have targeted water treatment br plants, the electrical grid, transportation br systems and other vital infrastructure.br Those hackers have targeted water treatment br plants, the electrical grid, transportation br systems and other vital infrastructure.br Water is among br the least mature br in terms of security, Adam Isles, head of cybersecurity br practice for Chertoff Group, via CNBC.br Stuart Madnick, an MIT professor of engineering br systems and co-founder of Cybersecurity at br MIT Sloan, warns that an attack that shuts off br water to the population is the main concern.br We have demonstrated in our br lab how operations, such as br a water plant, could be shut br down not just for hours or br days, but for weeks, Adam Isles, head of cybersecurity br practice for Chertoff Group, via CNBC.br Recently, EPA Administrator Michael Regan and br National Security Adviser Jake Sullivan sent a letter br to governors stressing the urgency of the threat. .br Recently, EPA Administrator Michael Regan and br National Security Adviser Jake Sullivan sent a letter br to governors stressing the urgency of the threat. .br CNBC reports that budgets, outdated br infrastructure and an overall reluctance to take br action may prevent necessary fixes from br being made before a serious attack.