The U.S. Department of Defense has disclosed a cyber breach involving one of its major personnel data systems, allowing unauthorized parties to access Social Security numbers and other personal information belonging to current and former service members.
A notification sent by the Defense Manpower Data Center (DMDC) to affected individuals said unauthorized users gained access to a vulnerable server as early as October. The Pentagon did not identify and address the security issue until July, approximately nine months later.
The Defense Department has yet to determine the exact number of records affected, while U.S. media reports have estimated that the incident could involve around 4 million Defense Department personnel.
The Pentagon said there is currently no evidence that the compromised information has been misused. However, the department acknowledged that the exposed data included, in some cases, service members’ occupational specialties as well as other personal information. The notification also indicated that the affected data was not encrypted.
The disclosure of occupational information has raised additional security concerns because such details could be combined with commercial datasets to create more comprehensive profiles of U.S. military personnel, including information about their finances, relationships, spending habits and online activity.
Cybersecurity experts warned that the information could potentially be exploited for phishing operations, intelligence profiling or attempts by foreign intelligence services to establish contact with military personnel.
The breach comes as the United States remains engaged in a military confrontation with Iran. U.S. military leaders have previously warned service members that their phones, online accounts and location data could become targets for adversaries.
The Defense Manpower Data Center serves as a central hub for information related to benefits, entitlements and medical readiness for Defense Department personnel, veterans and their families, while also supporting several key U.S. government sectors.
