Agency details results of an "interagency forensic investigation," plans for assisting affected individuals.
Hackers accessed the highly sensitive background check information of 19.7 million people, as well as the information of 1.8 million people who didn't even apply for background investigations, the Office of Personnel Management announced July 9.
The exposed data includes Social Security numbers, financial data, mental health details and other personal information.
Individuals who applied for background checks after the year 2000, using forms SF 86, SF 85 or SF 85P, were the most likely to have been exposed, OPM said, though those who applied before 2000 also face the possibility of exposure.
The breach likely exposes contractors and other private sector employees, in addition to federal workers.
"OPM has determined that the types of information in these records include identification details such as Social Security Numbers; residency and educational history; employment history; information about immediate family and other personal and business acquaintances; health, criminal and financial history; and other details," the agency said in a news release. "Some records also include findings from interviews conducted by background investigators and fingerprints."
OPM also announced that hackers had access to usernames and passwords used by background investigation applicants.
OPM took its electronic background check system offline on June 29; paper-based checks have since resumed.
OPM and the Defense Department will partner with "a private sector firm" to offer credit monitoring for at least three years to impacted individuals. That monitoring will include:
- Full-service identity restoration support and victim recovery assistance
- Identity theft insurance
- Identity monitoring for minor children
- Continuous credit monitoring
- Fraud monitoring services beyond credit files
OPM also announced a new website with resources about the breaches and promised a new dedicated call center to handle questions.
Notifications of the second breach exposure will begin going out soon, OPM said, and will include information on what to share with family members who may have been exposed through one's background check investigation.
OPM's tally of 21.5 million individuals affected by this breach includes some, but not all, of the 4.2 million the agency previously said were exposed in the first breach, which involved personnel files. According to OPM, 3.6 million of those 4.2 million are included in the 21.5 million whose Social Security numbers and other data were compromised when the background check database was breached.