For an update on the recent APT nation state attack that compromised Solarwinds, please see the following INFOSEC article, Cybersecurity Weekly: New SolarWinds backdoor found, affects MicroSoft & VMWare.
CISA (The Cybersecurity & Infrastructure Security Agency) has also issued: CISA Insights: What Every Leader Needs to Know About The Ongoing APT Cyber Activity and has created a supply chain compromise web page to consolidate resources.
Additionally, the FBI, CISA and ODNI (Office of the Director of National Intelligence) have issued a joint press release about the formation of a Cyber Unified Coordination Group (UCG) to coordinate the government’s response to this incident.