WASHINGTON — Chinese hackers in March broke into the computer networks of the U.S. government agency that houses the personal information of all federal employees, according to senior U.S. officials. They appeared to be targeting the files on tens of thousands of employees who have applied for top-secret security clearances.
The hackers accessed some databases of the Office of Personnel Management before federal authorities detected the threat and blocked them from the network, according to the officials. It is not yet clear how far the hackers penetrated the agency's systems, in which applicants for security clearances list their foreign contacts, previous jobs and personal information, like past drug use.
In response to questions, a senior Department of Homeland Security official confirmed the attack but said "at this time" neither the personnel agency nor the Department of Homeland Security had "identified any loss of personally identifiable information."
One senior U.S. official said the attack was traced to China, though it wasn't clear if the hackers were part of the government. The disclosure comes as a delegation of senior U.S. officials, led by Secretary of State John Kerry, are at an annual forum in Beijing to discuss the countries' commercial relationships and their wary efforts to work together on economic and defense issues.
Computer intrusions have been a major source of disagreement between the countries, and the Chinese can point to evidence that the National Security Agency went deep into the computer systems of computer network equipment maker Huawei and ran programs to intercept conversations of Chinese leaders and the military.
U.S. officials say the attack on the Office of Personnel Management was notable because while hackers try to breach U.S. government servers nearly every day, they rarely succeed.