Kaspersky has a very good research team which uncovered a lot of APT hacking groups including Russian ones so I don't see a reason why would they be a threat. But on the other hand Russian state can force them to snoop files and traffic from their clients but I doubt that will happen because everyone would stop using them and they would go bankrupt. Imo US government should use domestic antivirus solutions.
The Russian state might not care a lot about that possible consequence and still coerce them to include malware in the next update.