Security researchers with US cybersecurity firm Symantec said they have discovered a “highly sophisticated” Chinese hacking tool that has been able to escape public attention for more than a decade. The discovery was shared with the US government in recent months, who have shared the information with foreign partners, said a US official. Symantec, a division of chipmaker Broadcom, published its research about the tool, which it calls Daxin, on Monday. “It’s something we haven’t seen before,” said Clayton Romans, associate director with the US Cybersecurity Infrastructure Security Agency (CISA). “This is the exact type of information we’re hoping to...