Truth is, nobody knows shit because people in the administration and in most agencies in the US are mediocre at best. A single guy (Snowden) played cat and mouse with the US for years. And that guy is not particularly Einstein.
This is the mother of all hacks imo (regardless who's behind it). You can assume that all major financial institutions are impacted by this hack - solarwinds had 425 of the fortune 500 companies as their customers. Once hackers establish persistence in these networks it's really hard to get them out for good.
If everyone used Linux, then Linux would be the number one target of hackers. Hackers hack what people use the most, first. More bang for your buck, so to speak.
https://www.crn.com/news/security/microsoft-s-role-in-solarwinds-breach-comes-under-scrutiny Microsoft’s Role In SolarWinds Breach Comes Under Scrutiny Microsoft has become ensnared in probes surrounding the colossal U.S. government hack, with media reports and company messages focusing on Office 365, Azure Active Directory and a key domain name.
Those are SolarWinds servers. You need to understand how the hack occurred. Obviously you don't you dunce.