Credit Patrick Semansky/Associated Press
WASHINGTON â The F.B.I. secretly arrested a National Security Agency contractor in recent weeks and is investigating whether he stole and disclosed highly classified computer codes developed to hack into the networks of foreign governments, according to several senior law enforcement and intelligence officials.
The theft raises the embarrassing prospect that for the second time in three years an insider has managed to steal highly damaging secret information from the N.S.A. In 2013, Edward J. Snowden, who was also a contractor for the agency, took a vast trove of documents that were later passed to journalists, exposing N.S.A. surveillance programs in the United States and abroad.
The information believed stolen by this contractor â who like Mr. Snowden worked for the consulting firm Booz Allen Hamilton, which is responsible for building and operating many of the agencyâs most sensitive cyberoperations â appears to be different in nature from Mr. Snowdenâs theft.
The contractor arrested in recent weeks is suspected of taking the highly classified âsource codeâ developed by the agency to break into computer systems of adversaries like Russia, China, Iran and North Korea. Two officials said that some of the information the contractor is suspected of taking was dated.