KIPO recently refined its English website (in January 2019), and have provided one-click access system with the “ PCT ISA Portal “ where applicants will be able to easily process filing documents, check status, access PCT documents, and pay the fees via online.
The service path is : www.kipo.go.kr/en => click “PCT ISA Portal” => click “PCT Status”
Here is the link to check the status:
https://www.patent.go.kr/jsp/kiponet/ma/infomodifypatent/PctStatusInfoInput.jsp
Please enter your PCT application # and password on the ISA/202.
The list will contain the copies of the ISR/WO if they are issued.