What to Know About the Pentagon Breach Affecting Millions

It remains unclear what particular files were accessed and who was behind the incident. TIME has requested comment from the Pentagon. 

The length of the breach and the amount of personal information exposed present a security risk for many personnel linked with the department, and some experts say it makes other security compromises, like phishing attempts, easier for bad actors.

The DMDC collates personnel, manpower, training, financial, and other data for the Defense Department for healthcare, retirement funding, and other administrative needs. Its website says that based on FY2024 data, it has the records of more than 60 million people—including the military, civilians, contractors, family members, retirees, and veterans.

But the Military Times reviewed a Sept. 18 letter from the DMDC notifying its recipient of a data breach. The letter reportedly said it discovered on July 16 a security vulnerability in the center’s file-sharing system.