I cant say for sure for this, but I know for ghost hunting this is true--digital cameras are considered unreliable for spirit photography. The thing about them, especially cheaper ones, is that pixelation is not a complete process. What the camera does is take as many pixels as its supposed to, then "fills in" the rest. This is why people with ruddy faces (like me) may wind up looking like they have a whole head as bright as Rudolph's nose when some cameras take their picture. The drawback to this is less reliable pictures color-wise (you arent really catching on the camera what you see in real life) and flaws. The flaws are why these cameras are bad for spirit photography.

See, when they do the fill in, especially with night photography, you may find spots and dots on the consequent pictures, and what this is is a pixelation problem. I dont know how this works, but basically it encounters an error when trying to fill in spaces that are largly a single color, like in your photos the bright white sun or the all gray background. When that happens, it doesnt fill in the color, and a dot is left in its place. Ghost hunters mistake these dots for the spirit balls of energy often caught on regular film, when in fact all they are is the limits of the camera's functionality.

Looking at the spots on your pictures, my guess is you're looking at somewhat the same theory here. Before getting too excited, talk to an expert on how your camera works and see if this is true for it. If you keep seeing it, try to capture it with regular film as well. You also might want to do research on the area you found it at, especially if its the only place it shows up.

Good luck!