Moss and McDowell join rising star Adelaide Clemens (X-Men Origins: Wolverine, upcoming Mad Max: Fury Road), Kit Harington, and returning Silent Hill residents Radha Mitchell, Sean Bean and Deborah Kara Unger.
Hadida said: "Carrie has displayed her enormous talent across all genres from 'The Matrix' trilogy to 'Memento' and we are delighted for her to join the world of Silent Hill. She will certainly bring a new level of excitement to fans of the videogame franchise."
Director Michael J. Bassett said: "Malcolm is quite simply an icon of modern cinema and I've been a fan since I was a teenager when I managed to see 'A Clockwork Orange.' He has an amazing ability to bring new and unexpected dimensions to his characters and I know he will bring something unique and disturbing to Silent Hill."