The dark matter sweepstakes invites your guess. The winner gets dark matter money.
My guess was non baryonic quarks assembled into strange 1/2 spin hadrons in the technicolor range beyond the 100 hadrons we know (which makes their name absurd since they are invisible) and should be called Donuel-Bose condensates.

Simply put; it is the energy state condensate of the left over energy junk from the annihilation of matter and anti matter. :*)