MasWings
If able to get on with MASWings, you'd probably be looking at Kuching, Miri, or Kota Kinabalu. However, there are tons of Malaysian students that don't have jobs coming out of flight school. I highly doubt a non-Malaysian passport holder would be able to get an FO position. Command on type (ATR or Twin Otter) would probably be a different story. The DCA doesn't provide conversions/validations for foreign FOs.
If you have a Malaysian passport, you could try Sabah Air, or Hornbill Airways (Sarawak). I don't remember the name of the other one out of Sabah. The only other options would be as a flight instructor, which I wouldn't recommend in East Malaysia as flight training in the country is shrinking for lack of government sponsored funds for students, and they are sticking to the big three.
Another resource could be flylah.com.