How to reinstall a fresh copy of MyBB without data loss

[Devilshakerz]

You can save a backup of all files and the database for analysis later, then change your passwords for the server/hosting management panel, the email account it's tied to, etc., all the way down to MyBB administrator accounts; to make sure the filesystem is clean, you can:

• use some software (e.g. WinMerge on Windows) to list differences between the set of files than your board runs off and a fresh MyBB package and manually delete/restore files that might be malicious, or
  
• remove files (saving a copy of the uploads/ directory, and other ones if needed, like inc/plugins/, but you would have to review their content to make sure they don't contain malicious code) and upload files from the fresh MyBB package, upload inc/config.php (here is the code that generates it - it shouldn't contain anything else) and make sure the installation can connect to the database (with content intact) and restore the content in uploads/,
  

after that you would need to make sure there are no additional administrator accounts or unsafe settings (like allowed HTML in posts); the guide at https://docs.mybb.com/1.8/administration...rotection/ should help, but also take a look at other security-related ones at https://docs.mybb.com/1.8/administration/security/.

The DVZ Integrity Tools plugin can point out specific differences between current and original files as well as changes in the database structure.