I have 5 instances with google cloud, all running WordPress by bitnami. At 11am today, all websites are inaccessible...that's weird because I didn't alter anything and suddenly, not 1 website, but all websites down at the same time. Did try to stop and start again the instances, nothing work...SSH and FTP still accessible. I create a new instance with fresh WordPress, it is working. Any idea what happened to it?
**Case resolved. Malware found in the plugin directory. Please read my answer below for more info.