Malaysia's decision to seek a review of the International Court Of Justice's Pedra Branca judgement may well be an attempt by the Government Of The Peoples Republic Of China to extend its collection of artificial islands to the Middle Rocks, a rocky outcrop to the south of Pedra Branca, but which the ICJ decided belonged to Malaysia.
Malaysia has since 2008 when the decision was handed down agreed to work with Singapore to arrive at a mutually acceptable delineation of the area, given the competing maritime claims that arise out of the ICJ's decision. Meetings have been held between the countries since 2008,and in 2010 there was agreement to conduct a joint hydrographic survey in and around Pedra Branca, and Middle Rocks.
Now however Malaysia is seeking to have the entire decision reviewed, and it does seem as if it is doing so with little basis. The determination to push on with the matter regardless raises the possibility that Malaysia will not mind losing ,so long as the Pedra Branca decision and all prior negotiations are rendered meaningless as a result of the matter remaining unresolved, or at least in contention due to perceived grievances on Malaysia's part.
That would allow Malaysia to claim that the matter remains in dispute, and justify a more aggressive assertion of sovereignty ,such as island building, like China has in the South China Sea. Malaysia's leadership, especially under Prime Minister Najib has shown little appetite for such aggression , but China of course is an old hand at that game. China has also shown itself willing to ignore decisions of an international tribunal,and this far defy international criticism for doing so.
Given that Malaysia and especially Najib are now very much beholden to China it is likely that this legal challenge is being orchestrated by China with the ultimate aim of controlling the eastern mouth of the Singapore Strait. It probably expects that Singapore will fold, just like the Philippines ,regardless of the legal position.