Here are some procedure need to follow when site getting hack:
Step 1: First, you need to identify how the hackers enter your system.
Step 2: After identifying the vulnerability ask your admins to move all the data in a safe place with high security.
Step 3: This way we can stop the hackers from stealing the data.
Step 4: Another alternative way is try to connect with the Free website malware removal service providers (Cwatch)
Note: Install some website security tools at server once it is cleaned so that you can avoid the attacks in future.