Navigate to the location of the files, open it and check the content of it. Maybe you get an idea what their purpose is. The file names seem to be random and definitely not part of the standard Nextcloud package.
Next I would move the files to a directory outside of the Nextcloud root and trigger the the security scan again.
Hello
I found these two files under a roundcubemail installation, so obviously nothing related to my Nextcloud installation.
I renamed / moved these two files … but got same error from the Nextcloud updater.
By default the previous status is shown on the status page. You might need to trigger a new scan manually by clicking on the relevant key word in the message.
It doesn’t work.
The two mentionned files does not even exist anymore (as I deleted them) but still appears as unexpected files and so block the upgrade process.
Error is : The following extra files have been found: