Todd Gaines’s review published on Letterboxd:
I am not sure how many people are even aware of Warning Sign, but it is definitely worth watching.
Warning Sign has an Outbreak / The Thing vibe. Sam Waterston gets to play an action hero, and Kathleen Quinlan is the minimum wage security guard heroine. Yaphet Kotto and Jeffrey DeMunn have hefty roles as well.
Warning Sign is a film ahead of its time. It is dated, but highly relevant. Seek it out.