Weird graphics artifacts that randomly pop up

[Nullifidian]

Since the past few weeks I'm having some trouble with my graphics. This kind of stuff keeps appearing:




This seems to appears randomly. sometimes I can go for days without getting this and other times I get this on start up. They're these triangles that appear and disappear at random spots on my display whenever something moves (like my mouse, or an ad on a website etc.) After a random while it just disappears again as if nothing happened. What could be the cause and how to fix? Because this is beyond annoying..

Let me know if you need any specific information.