MOSCOW: Russia’s Federal Security Service (FSB) said on Thursday it had uncovered a US National Security Agency (NSA) plot using previously unknown malware to access specially made so-called backdoor vulnerabilities in Apple phones.

The FSB, the main successor to the Soviet-era KGB, said several thousand Apple phones had been infected, including those of domestic Russian subscribers.

Neither Apple nor the NSA immediately responded to emailed requests for comment.

The Russian spy agency also said telephones belonging to foreign diplomats based in Russia and the former Soviet Union, including those from Israel, Syria, China and NATO members, had been targeted.

“The FSB has uncovered an intelligence action of the American special services using Apple mobile devices,” the FSB said in a statement.

The United States is the world’s top cyber power in terms of intent and capability, according to Harvard University’s Belfer Center Cyber 2022 Power Index, followed by China, Russia, the United Kingdom and Australia.