The Cybersecurity and Infrastructure Security Agency (CISA), Federal Bureau of Investigation (FBI), Environmental Protection Agency, and Department of Energy have issued a joint warning to critical infrastructure organizations in the United States regarding increasing cyber incidents targeting operational technology and industrial control systems. These federal agencies are urging immediate action to strengthen cybersecurity defenses, particularly for systems connected to the public internet. Key recommendations include removing internet access from operational technology devices, changing default passwords to strong and unique alternatives, securing remote access with strong credentials and phishing-resistant multifactor authentication, segmenting operational and information technology networks, and ensuring the ability to operate systems manually in case of a cyber incident. They also emphasize the importance of working closely with third-party vendors and service providers to prevent misconfigurations and reduce vulnerabilities. The agencies have provided a list of resources to help organizations reduce their exposure and improve their cybersecurity posture. For further information and to access the list of resources, refer to the Joint Advisory.