Less than 24 hours after the recent hack against the Office of Personnel Management (OPM) was announced to have reached 21.5 million affected individuals, its director has stepped down.

In a statement, Katherine Archuleta wrote that it was “best for me to step aside” from leading the agency charged with managing federal employees. She had been in the position for just over two years.

This is quite a reversal for the OPM boss. Speaking before a Senate hearing on June 23, Archuleta said, "I'm as angry as you are that this is happening... I am dedicated to ensuring that OPM does everything in its power to protect the federal workforce and to ensure that our systems will have the best cyber security posture the government can provide.”

Yet she insisted that no one at the OPM was to blame for the breaches. "If there is anyone to blame, it is the perpetrators," she said.

The hack has affected huge number of federal employees.

"If you underwent a background investigation through OPM in 2000 or afterwards (which occurs through the submission of forms SF-86, SF-85, or SF-85P for either a new investigation or a re-investigation), it is highly likely that you are impacted by the incident involving background investigations," OPM officials warned in an update published Thursday. "If you underwent a background investigation prior to 2000, you still may be impacted, but it is less likely."

SF-86 is the form that all federal employees are required to fill out to obtain a security clearance.

Earlier this week, FBI Director James Comey told a Senate panel that he “was sure” the hackers now had his personal information.

"I'm sure the adversary has my SF-86 now," Comey said. "My SF-86 lists every place I've ever lived since I was 18. Every foreign travel I've ever taken. All of my family, [and] their addresses."

The OPM did not immediately respond to Ars’ request for comment.