A news report claiming a compromise of U.S. companies’ supply chains by Chinese spies has triggered an extensive search for evidence that has so far turned up nothing.

U.S. and British security agencies have backed statements by Apple and Amazon Web Services disputing an explosive news report claiming that the Chinese compromised hardware used by the tech giants.

Manufacturers of the millions of business PCs, laptops and servers using Intel chips with a newly discovered vulnerability are scrambling to roll out patches.

Pentagon scientists say they could stop 40 percent of current cyberattacks by producing secure computer chips. The System Security Integrated Through Hardware and firmware, or SSITH, program is looking for help from industry.