I got the book (in German) maybe around 1990 from a children's library, so it was probably a young adult novel. I believe to remember that the title of the book was the name of the protagonist, a youngish woman name 'Crissy', or 'Carrie' or similar (the latter virtually impossible to search for, due to the Stephen King novel), but this might have been a translated title. The book was probably part of a series.
I remember the following:
The (soldier) woman awakes from some malfunctioned cryosleep pod in a mountain bunker, and makes her way to the surface to find out that she has been sleeping way longer than planned, and that the Earth has been devastated and conquered by some alien force.
While leaving this mountain bunker, she triggers an alarm of an other fraction of humans who still live in another bunker. They send a search party after her.
During her voyage on the surface she encounters civilians which have fallen behind in technology and can barely make fire. She gives them a lighter.
The aliens have manipulated some humans to convert them to fighters/'handymen' for their purposes and those have significant control over their bodies. I think one of them was able to detect and neutralize some poison in his body (just like Paul Atreides after, you know, drinking the worm water). Part of the story is from the perspective of one of these fighters, and I think he kind of questioned the motives of the aliens.
I am already looking for it for a long time to reread it for the good old times sake. I googled (no luck), asked the library where I got the book (they only keep books and catalogs for 10 years) and even ChatGPT (they fantasized something, but no leads), so I am afraid it might have been some pulp fiction book.