Disregarding all the craziness here that suggests Malurians are pre-warp for some reason, even though they're clearly not, they are referenced quite a bit in the Rise of the Federation novels where Garos (the Malurian from the Enterprise episode) is an ongoing villain across three novels having been exiled from Maluria. Maluria (the system) is even referenced in star charts as recently as Picard, although, of course, this doesn't tell us anything about Malurians.
One 2007 TokyoPop comic deals with the aftermath of The Changeling, and is our only real look at a Malurian who was apparently the lone survivor of the attack:
We've never seen Malurians since that TokyoPop comic, even though Maluria itself apparently has the Malurian System Medical Station (in a TNG Okudagram).
The Malurians of "Alpha Maluria VI" feature heavily in the 1992 novel Faces of Fire, which may be set before or after The Changeling during the five-year mission. If before, it's possible that Alpha Maluria VI is one of the four inhabited planets of the Maluria system. If after, it's possible that this is confirmation of multiple colony worlds by the warp-capable Malurians. Memory Beta lists the species as "Alpha Malurians", presumably to differentiate, but a glance through the novel confirms that they are only addressed as Malurians throughout, and it's unlikely they were intended to be a different species.