Note that if you follow the above users recommendation on using a debit card at an ATM, that Malaysia is a country that requires you to be added to a whitelist (the whitelist of which interestingly includes Australia) in order for your debit card to be used at all. This is true at least for Scotiabank and Tangerine. The whitelist is a list of countries with high debit card fraud. It was not enough for me to just call my bank to tell them I'm travelling to Malaysia and have them add a note (which I had already done!). They had to have a supervisor add me to the whitelist and the first call centre agent you talk to may not be aware of this! Even more frustrating, the supervisor was not available during Canadian night hours (EST 1am to 8am).
Malaysia is a wonderful country though. Just don't take the intercity train unless you're curious what a squat toilet that opens to the tracks below looks like.
If you're transferring through Singapore for whatever reason, you could cash them there and exchange to Ringgit in the airport (exchange offices available land and airside). You lose an extra 5% above the normal CAD exchange rate (which is actually competitive via cash). Not entirely sure if the office will have enough cash, but there are lots of exchange booths and MYR is a commonly exchanged airport in SG for obvious reasons.