The breach of US security clearance information in the cyber-hacking of the federal government’s personnel office poses a “significant counterintelligence threat” and could compromise the identities of American spies abroad, senior US officials said on Thursday. Testifying before a US House of Representatives panel, Director of National Intelligence James Clapper said there were no signs yet of
any “nefarious” use of data accessed in the hacking of the Office of Personnel Management, which was disclosed in June. But he expressed concern to lawmakers on the House Committee on Intelligence that the information could be used to expose U.S. personnel operating undercover. Some US officials, speaking on condition of anonymity, have said the OPM attack originated in China.