Private companies paid by who?
CrowdStrike - paid for by the DNC
Fidelis Cybersecurity - paid for by the DNC
FireEye's Mandiant - CEO at the time was Kevin Mandia, who's a known associate of Hillary Clinton and also publicly a democratic financial supporter.
SecureWorks - owned by Michael Dell, a known donator to the Clinton Foundation
ThreatConnect - not much info, but also explicitly only said "likely"
Trend Micro - Hillary and DNC are customers of Trend Micro, and they also did not actually say anything at all about a connection to Russia.
Additionally, the reports don't say it was Russian. They say the tools are ones that Russians have been thought to use, with no context into whether everyone uses these tools, to what confidence level they believe that Russians actually use these tools, no context as to whether someone would deliberately use these tools to make it look Russian, or virtually anything at all that substantiates this argument. They also almost universally use phrases like "likely" or "points to". Trying to characterize this situation as confirmed is just outright wrong.
Anyway, this is exhausting. Hyperbole becomes fact and I'm tired of having to disprove hyperbole.