Microsoft says China-backed hackers are exploiting Exchange zero-days

Microsoft is warning customers that a new China state-sponsored threat actor is exploiting four previously undisclosed security flaws in Exchange Server, an enterprise email product built by the software giant. The technology company said Tuesday that it believes the hacking group, which it calls Hafnium, tries to steal information from a broad range of U.S.-based organizations, including law firms and defense contractors, but also infectious disease researchers and policy think tanks. Microsoft said Hafnium used the four newly discovered security vulnerabilities to break into Exchange email servers running on company networks, granting the attackers to steal data from a victim’s…