During the past year or so, we've seen a critical rise in infected Wordpress websites on our servers. Most of the time it's caused by backdoors that have been uploaded through a slider-plugin (which most of our customers somehow knew could be abused but still chose to use). Through these backdoors, a ton of randomly-named .php files are uploaded. This causes spam to be sent from the client's account. I was wondering if there's anything we could do to prevent this? I've thought about disabling file_uploads, but I'm not sure that would really work, or if it would be too much of an inconvenience. We're daily running maldet, but this tool surprisingly hasn't detected a single one of these backdoors yet. It seems to only find malware encoded with base64.