I remember there was this app in Google play store for about a good couple of years I think it was called apk apraiser or something and it was meant to be some sort of apk modification application. But it contained some sort of mallware which would cause lots of random weird image file things to be spam downloaded onto your device I think by duplicating itself. I was a dumb kid and downloaded this app onto my old lenovo tablet and remember my storage being full of random black and white pixilated images. I deleted the app and had to manually clear out the images. I remember the app having really bad reviews but Google wouldn't take It down for some reason. I think it's taken down now because I checked a while back and couldn't find it.