mplugin Redirect Malware

Hi I keep getting this mplugin.php redirect malware. I run wordfence scan at it’s highest sensivity and delete it. But it has appeared again after a month or so. I removed it again I am noticing that the function.php file in wp_admin was edited or added at the same time as this mplugin file. I don’t see anything that sticks out from me in this file they may have edited.

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