This is a false positive.
This file is used with integrated restoration. It of course has the ability to write to files (file_put_contents) otherwise you could not extract anything. It of course has the ability to delete files (unlink), otherwise it could never perform the clean-up step where it removes the installation directory and you'd never be able to use your site. It of course has the ability to change the PHP error reporting because a too verbose level would possibly break the AJAX requests.
Please contact your host and let them know this is a legitimate file they should whitelist.
Nicholas K. Dionysopoulos
Lead Developer and Director
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