Aflac said Friday customer health data and Social Security numbers were hacked, but that it stopped the cyber intrusion within hours and the attack did not include ransomware.

Aflac, one of America’s largest insurance providers, confirmed on Friday that it had been the victim of a cyberattack that stole the personal information of its customers, including Social Security numbers.

Aflac says that it has identified suspicious activity on its network in the U.S. that may impact Social Security numbers and other personal information, calling the incident part of a cybercrime campaign against the insurance industry. The company said Friday that the intrusion was stopped within hours.