OPM Announces More Than 21 Million Affected by Second Data Breach

The federal personnel agency announced Thursday a massive hack.

More than 21 million Social Security numbers were compromised in a breach that affected a database of sensitive information on federal employees held by the Office of Personnel Management, the agency announced Thursday.

That number is in addition to the 4.2 million social security numbers that were compromised in another data breach at OPM that was made public in June.

Of the 21.5 million records that were stolen, 19.7 million belonged to individuals who had undergone background investigation, OPM said. The remaining 1.8 million records belonged to other individuals, mostly applicants’ families.