The most popular Malayalam version of the Valmiki Ramayan is the Adhyatma Ramayanam Kilippattu written by Thunchattu Ezhuthachan. It is especially read during Malayalam month of Karkidakam, which is also known as the Ramayana Masam. You can now download Malayalam Ramayana Text in PDF format for free. The PDF version is in verse format.
You can download here at Google Drive - Malayalam Ramayan (Please note that you will need to login to gmail to view the document and save. The document is shared with all there is no need for permission.)
The PDF version is from the Mobile Malayalam Ramayan version of P Harikumar.
You will need pdf reader installed in your computer or laptop to read the Ramayanam.