In June 2015, the OPM announced it had been the target of a cyberattack compromising the records of some four million people. The hack, which had reportedly started in March 2014 and lasted at least four months, was noticed by the OPM only the following year.
The investigation into the hack found out that the records of more than 21 million people have been stolen. Shortly after the number was announced, OPM chief Katherine Archuleta resigned.
On July 9, 2015, the results of the investigation showed that the stolen data included personal, financial and health data on current, former and prospective federal employees, including the fingerprint records of more than a million people. Affected are also individuals who have applied to obtain security clearance as well as the references they have listed.