I think I already told you about this too, if you want to delete spam image, make sure you check its history first, so if the image is existing and needed for wiki, just revert it to original image, so please just don't delete it immediately like you do.
Also since you have Content Moderator rights, you also have Rollback access, so when you want to undo page that got spammed, just use rollback button not undo button like you always do, it'll back immediately to the last user who edit its page. And if you want to undo page, please don't add the words like you do, because that just make you same with the spammer and the spammer will be happy if you do that.
I think we already talk about you can't just delete spam file without checking its history first? And today you just delete spam image that actually needed for this wiki? If I ask, why you always do that? Even though we already told that you should check its history first before you decide to delete it, if you decide to delete it, at least you immediately restore it to the right file and uncheck the spam history and only check the right one or if you don't know just revert it without delete anything.