The Chinese government sponsored hacking group known as "APT 10" or "cloudhopper" is expected to be charged with a multiyear scheme of breaking into U.S. technology service providers in order to compromise the networks of their clients. "The service providers often are not the initial victim; instead, hackers sometimes breach a client company in order to jump into the provider's systems, from where they can then leapfrog into other client networks." U.S. officials say that these instances of espionage are the most damaging attacks that Beijing has sponsored on American service providers such as cloud storage and the remote management of technology infrastructure. Scores of U.S. companies and government agencies have been affected by the attacks. "We view it as the platform the Chinese are using for whatever they need," Rob Joyce, a senior official at the National Security Agency, said in an interview in October. That could include additional espionage, theft of intellectual property and, potentially, groundwork for disruptive operations, Mr. Joyce said. "If they get into a managed service provider, then they can go to any of the customers of those providers," Mr. Joyce said. "So we are really concerned. And that's why you are seeing the government saying, we've got to deal with it, push them out, make sure they don't have that toehold." "For Western business environments, I think APT 10 is probably the most significant Chinese threat group that's out there," Mr. Nish said.