After having a banking account for your monthly salary deposit, with limited amount of cash or saving in hand, there is very limited investment tools for you to choose in Singapore.
You still need to send back some money to Malaysia for your family, your house instalments, your insurance, your unit trust top up, etc. Thus, in your initial month in Singapore, you have left with limited amount of net cash for investment. Nevertheless, we still need to have saving ourselves. By the way, there is no CPF, EPF for non-Singaporean, for us when we started work without PR. We must have discipline ourselves to save for our golden age.