If you want to research this, the terms to look for is something like "Russian hybrid warfare goals and objectives in Europe" (can also try greyzone warfare).

For example, here's a CSIS (American think tank) report: https://www.csis.org/analysis/russias-shadow-war-against-wes...

Put simply, the goal is to add friction to anything NATO tries to do to aid Ukraine, and/or generally to improve its posture against Russia, while also trying to crack apart and erode both broad based and elite support for acting against Russia.