I don't know what comprises dark matter exactly but I know where it came from. It came from the annihilation of matter and anti matter, Besides the energy release from matter being converted, there is a certain amount of residue in which the energy converted to matter. But what kind of matter? Certainly one which had the property of gravity but not made of normal atoms.
How about an experiment to create dark matter? We need a shitload (scientific term) of antimatter and measure what dissappears in annihilation radiation (E) and how much is converted to Mass and how much disappears (C). This will be a first measurment. The results will give us more understanding and questions.

I have a sneaking suspicion the mass is all quarks and neutrinos with no protons, neutrons and electrons. If they loan me the LHC I might blow it up but at least learn something new.