Hackers swiped Social Security numbers from 21.5 million people -- as well as fingerprint records and other information from background check investigations -- in the massive breach earlier this year of federal personnel files, the government acknowledged Thursday. The Office of Personnel Management included the findings in a statement Thursday on the investigation into a pair of major hacks believed carried out by China. "The team has now concluded with high confidence that sensitive information, including the Social Security Numbers (SSNs) of 21.5 million individuals, was stolen from the background investigation databases," the agency said of the second breach, which affected background investigation files. OPM said it is "highly likely" anyone who underwent a background investigation through the agency since 2000 has been affected. The 21.5 million number mostly includes those who applied for one, but also 1.8 million others, "predominantly spouses or co-habitants of applicants." OPM said these records include "findings from interviews conducted by background investigators and approximately 1.1 million include fingerprints." The agency said they have no information at this point to suggest "any misuse or further dissemination of the information that was stolen from OPM's systems." Despite agency pledges to help those affected with credit monitoring and other assistance, the latest numbers are sure to deepen concerns about the risks those affected face.