The US government has initiated an investigation into UnitedHealth following a ransomware hack of its subsidiary, Change Healthcare, last month. This cyberattack, which affected a company processing 15 billion healthcare transactions annually and impacting 1 in 3 patient records, has revealed persistent vulnerabilities in health care cybersecurity defenses. Despite the ongoing issues, Change Healthcare has made progress in recovery, restoring some functions with the help of Amazon's cloud services and expects to ramp up the system fully over the course of this week. UnitedHealth has responded by offering substantial loans to some healthcare providers affected by the attack, while calls for robust financial assistance have been made. Federal officials and industry executives have been criticized for their longstanding knowledge of these vulnerabilities without taking adequate action to prevent such incidents.