The most likely cause of the server crashing and the application being inaccessible is that the unauthorized software installed by the update is malware that corrupted the system files or compromised the security of the server. To restore access to the application while minimizing downtime, the administrator should scan and remove any malware from the server, and then reformat the server and restore the image from the latest back-up. This will ensure that the server is clean and has a working configuration of the application. Verified Reference: [How to Remove Malware from a Server]