I can't say with certainty, as I don't follow the Civilian or Matriarch models closely, but I think a fake would be much more likely to be marked as VG-10 than ATS-55. My guess is that it's an authentic older model.
I doubt that this is fake. Most likely is real. This is an older model. 10+ years. Until few years ago there were almost no fakes, which look very close to real Spydercos except black UKPK
"People sleep peaceably in their beds at night only because rough men stand ready to do violence on their behalf"