Open up Photofiltre and open a new file 800×600 pixels.
Take the fill tool and fill the whole thing with black.
Click (O) on your keyboard or click the Spray tool and set your settings as mine
Now just spray everywhere with the color white until yours looks somewhat like mine: screen shot
Then using black as your color spray over everything because you don’t want too much white so that the scratches look right. screen shot
Now just click a lot until you are satisfied with your result.