The U.S. National Security Agency (NSA) was planning to exploit specifically created backdoor flaws in Apple phones, according to a report released on Thursday by Russia’s Federal Security Service (FSB). This malware was previously undisclosed.

Several thousand Apple phones, including those of domestic Russian users, have been infected, according to the FSB, the principal successor to the KGB of the Soviet period.

The Russian intelligence service added that targeted telephones included those from NATO nations, Israel, Syria, and China, as well as those belonging to foreign diplomats residing in Russia and the former Soviet Union.

The FSB released a statement saying that it has “uncovered an intelligence action of the American special services using Apple mobile devices.”