https://www.reuters.com/article/us-cyber-solarwinds-microsoft/microsoft-failed-to-shore-up-defenses-that-could-have-limited-solarwinds-hack-u-s-senator-idUSKBN2AP2XD

Microsoft Corp's failure to fix known problems with its cloud software facilitated the massive SolarWinds hack that compromised at least nine federal government agencies, according to security experts and the office of U.S. Senator Ron Wyden.