After Russian intelligence launched one of the most devastating cyber espionage attacks in history against U.S. government agencies, the Biden administration set up a new board and tasked it to figure out what happened — and tell the public.

State hackers had infiltrated SolarWinds, an American software company that serves the U.S. government and thousands of American companies. The intruders used malicious code and a flaw in a Microsoft product to steal intelligence from the National Nuclear Security Administration, National Institutes of Health and the Treasury Department in what Microsoft President Brad Smith called “the largest and most sophisticated attack the world has ever seen.”

The president issued an executive order establishing the Cyber Safety Review Board in May 2021 and ordered it to start work by reviewing the SolarWinds attack.

But for reasons that experts say remain unclear, that never happened.

Nor did the board probe SolarWinds for its second report.

A full, public accounting of what happened in the Solar Winds case would have been devastating to Microsoft. ProPublica recently revealed that Microsoft had long known about — but refused to address — a flaw used in the hack. The tech company’s failure to act reflected a corporate culture that prioritized profit over security and left the U.S. government vulnerable, a whistleblower said.