OPM Hack: Is China Behind The Cyber Attack That Affected More Than 21 Million People?

The United States Office of Personnel Management has released more information on just how severe the cyber attack it fell victim to in early June was. On Thursday, the OPM announced that the hack affected more than 21 million Americans, according to Reuters. The victims of the hack are people who underwent background checks for security clearances with the office between 2000 and the day of the attack, the reports said.

Compromised information of applicants include Social Security numbers, birth dates, job pay history, health insurance, life insurance, pension information, ages, gender and race data.

The OPM believes that China is behind the cyber attack. On Thursday, China's Foreign Ministry said the accusation is an "absurd logic." Even though a massive amount of information was compromised, the OPM said that since the initial hack, there has not been "any misuse or further dissemination" of the stolen information.

Out of the hacking victims, 1.8 million people are believed to be non-applicants for security clearances, but spouses and co-habitants of applicants. Non-applicants' names were in the system because of references and other personal information that is required on security-clearance forms.

Upon infiltrating the system, the hackers targeted "four different segments," one of which houses digital paperwork filled out by employees with security clearances. OPM spokespeople originally said that information did not include names of employees' family members but have since recanted.

Applicants who sent in information prior to 2000 were most likely not affected by the hack, the OPM said.

The hack was only brought to light because the OPM was in the process of updating equipment and systems. It immediately contacted the Department of Homeland Security and FBI upon realizing the "anomalies," according to ABC News.