In an interview he had given to the German magazine Der Spiegel, in addition to setting out the co-operation of the German secret services with the NSA, revealed and who related to him a notorious Stuxnet virus that 2010 was used in Iran's nuclear facilities.
"The NSA and Israel co-wrote the Stuxnet code," Snowden said when asked if the NSA had any involvement in the Stuxnet program.
The US has not officially confirmed its participation in the Stuxnet program. However, when the New York Times published an article about a year ago about malware and reported that the US and Israel collaborated for this malware, the Ministry of Justice launched a survey to find out who is behind the leak.
At present, reports say that retired General James Cartwright, the former deputy chairman of the Joint Chiefs of Staff, is the main suspect of the investigation.