This is the southwest-facing side of the rock in
NY9717 : Cup-marked rock, Sunny Brow which has at least five rounded cups on its northeast face, two very obvious indeed. This face has a row of eight very evenly-spaced holes, not as rounded as the ones on the other side, and following a line of natural weakness, but still looking unlikely to have been formed by natural erosion. This rock is, however, not documented in the reference for the area. I could quite believe that the markings this side were of modern origin, but the ones on the far side look much more like the markings on several other ancient stones in the immediate vicinity (one the subject of a recent interpretive sign despite being in an MOD firing range and not frequently visited). Given how obvious this rock is, I am surprised that the book doesn't mention it at all, even if only to say that it is not considered prehistoric (graffiti dating to 1959 is mentioned on another such rock a short way to the east).
Reference: "Prehistoric Rock Art of County Durham, Swaledale and Wensleydale", Stan Beckensall and Tim Laurie, County Durham Books, 1998, ISBN 1-897585-45-4