Thank you. It shows just some bots trying to corrupt plugins files (that doesn’t exist in my installation).
But what I am wandering about is how Googlebot is informed about those links (that didn’t exists).. if sitemaps could be corrupted or something else?
I have absolutely the same problem. But how could I detect, where those 404 starts from? When I open my Webmaster tools, it shows me that those links goes from another 404 (which doesnt exist).