SolarWinds hack was 'largest and most sophisticated attack' ever - Microsoft president

Microsoft's President Brad Smith speaks at the Web Summit, in Lisbon, Portugal, November 6, 2019. REUTERS/Pedro Nunes/File Photo

WASHINGTON (Reuters) - A hacking campaign that used a U.S. tech company as a springboard to compromise a raft of U.S. government agencies is "the largest and most sophisticated attack the world has ever seen," Microsoft Corp President Brad Smith said.

The operation, which was identified in December and that the U.S. government has said was likely orchestrated by Russia, breached software made by SolarWinds Corp, giving hackers access to thousands of companies and government offices that used its products.