A significant cyberattack on UnitedHealth's Optum subsidiary, attributed to cybercriminals, has severely disrupted operations across the U.S. healthcare sector. The attack, which involved the theft of 'millions' of records according to the hackers, has led to widespread issues including billing delays, frozen payments, and security concerns. Healthcare providers and pharmacies are among the hardest hit, with many scrambling to find alternative ways to fill prescriptions. The incident has affected the ability to process prescriptions for nearly 10 days, leaving patients and pharmacies frustrated and leading to a disarray in the U.S. prescription drug market. The ransomware gang behind the attack has been previously targeted by law enforcement, suggesting a resurgence. The American Hospital Association described the fallout as 'the most serious incident of its kind against a U.S. healthcare organization'. The attack's impact on prescription access has been described as a 'threat to life', highlighting the severity of the situation.