The site got infected again

After moving to the WPMU DEV hosting my site got infected twice, it never happened before, and I'm very upset with this, can you check why/how it is happening and give me concrete information how we can prevent this? **** This is very oversimplified. Please see this ticket: https://premium.wpmudev.org/forums/topic/1-where-is-my-ticket-2-what-happened-to-my-site-3-where-are-the-blog-pages