In physics, there is never confirmation. At best there is "measurement agrees with the model as exactly as it is currently possible to measure". The standard model is confirmed in that sense.

Dark matter is a problem from cosmology and astronomy, that maybe has a solution in an extension to the standard model. Maybe it hasn't and that solution will come from elsewhere, maybe there is a totally cosmological explanation after all. In all cases, the dark matter problem is not a contradiction to the standard model in our current experiments. If there were a particle-physics explanation to dark matter, it would be a sufficiently small alteration to the standard model that our current experiments couldn't tell the difference, to within experimental error. That's how confirmation and new models in physics work.