Apparent effects of dark matter have been “discovered” so many times in the last decade that you may by now feel a bit jaded, or at least dispassionate. Certainly I do. Some day, some year, one of these many hints may turn out to be the real thing. But of the current hints? We’ve got at least six, and they can’t all be real, because they’re not consistent with one other. It’s certain that several of them are false alarms; and once you open that door a crack, you have to consider flinging it wide open, asking: why can’t “several” be “all six”?- Professor Matt Strassler.
The evidence that something is causing the universe to behave at astronomy scales in a manner inconsistent with general relativity acting primarily on luminous matter is overwhelming and largely internally consistent. Most commonly these effects are attributed to "dark matter" and "dark energy."
But, the evidence that particular experiments have actually discovered new kinds of particles that cause these effects is not currently compelling. They are seeing "something" that gets tagged as an event, but it is very hard to distinguish those events from experimental error and unknown but pedestrian background effects.