Can someone help review our WP visitor logs for possible internal hack?

My business has been using an outside developer who has complete access to our site. Lately we have noticed many business anomalies that just don’t make sense and we are starting to suspect our developer may be managing a redirect within our server. We lack the technical skills to know what to look for and a review of our server visitor logs just makes us more confused and suspect. For instance our visitor log shows many random “xmlrpc.php” entries, but not sure if they are normal or not. We have been unable to locate any service or individual to assist us, so I’m hoping maybe someone in this community can make a suggestion, or possibly help by reviewing our logs and setup. I really hope we are not imposing, but we’re at our wits end. Thank you!