UnitedHealth says files with personal information may have been taken in the cyberattack earlier this year on its Change Healthcare business. The company said Monday after markets closed that it sees no signs that doctor charts or full medical histories were released after the attack. It may take several months of analysis before UnitedHealth can identify and notify people who were affected. UnitedHealth bought Change Healthcare in a roughly $8 billion deal that closed in 2022 after surviving a challenge from federal regulators.