It's a busy time for security.  The Cybersecurity & Infrastructure Security Agency has released a number of guidance documents on SolarWinds and ActiveDirectory/M365 compromises as well as the recent Microsoft Exchange vulnerabilities that are being actively exploited.
Blog Post (including Links):
https://grassrootsecurity.com/2021/03/10/cisa-guidance-on-solarwinds-ad-m365-and-exchange-remediations/