That's not quite right. A better analogy would be:

"Imagine being told there's loads of bugs in your system and it's constantly breaking, and even though no-one can show you a single one of these bugs, tons of users are complaining."

That would fit the situation better: There's only one kind of indication that these things exist.

There's been some pretty specific observations of dark matter like galaxies which have been shown to have varying proportions of DM, there have been measurements where scientists have actually localised the dark matter, i.e. mapped where it should be concentrated based on the perturbation of nearby stars.