Singapore Airlines has round-trip flights from Seattle (SEA) to Kuala Lumpur (KUL) for $540 with a connection. Flights January to May. Departures on Tuesday and Thursday. Extended Weekends available.
Note: Some small OTAs on SkyScanner have this for $508. If you plan on booking there, beware of any site that charges a fee to cancel a ticket within the 24-hour “free” period. Use unknown booking sites at your own risk.