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 confirmed today that it was breached by hackers, who may have stolen sensitive information from its millions of customers. Here’s what to know. Aflac Incorporated (NYSE: AFL) was the most recent target of a “sophisticated cybercrime group” that has led a campaign against a number of insurance companies in recent weeks,

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.