Executive search firm Korn/Ferry International Inc. (NYSE: KFY) reported its computer network was the target of a criminal data security breach. The company reported that it immediately took steps to contain the breach and investigate the source, and it has called in a digital risk management and investigations firm.

Korn/Ferry is also working with law enforcement.

Korn/Ferry reported the intrusion is in the category of “advanced persistent threat” and consistent with state-sponsored cyber criminals who use sophisticated tool and techniques to access databases.

It does not appear that any information that may have been gleaned by the attack has been misused, according to Korn/Ferry. The databases that were impacted were not designed or structured to collect credit card, payment card, bank account, Social Security numbers, government ID information or health information.

Korn/Ferry ranks as the largest provider of retained search in the U.S.