Odd Script File Trying to be Loaded

This is an odd query I have and wondered if anybody can shed some light on it?

We have a number WordPress multi-site (formally Mu) install, but on nearly all the sites on multiple installs we are getting this script tag…

<script src="https://[parent-domain]/?dm=[random-string]&amp;action=load&amp;blogid=1&amp;siteid=1&amp;t=401255033&amp;back=[this-sites-domain" type="text/javascript"></script>

I was wondering if anybody knows what this is all about?

Thanks.

In Network Admin > Settings > Domain Mapping > Domain Options, uncheck Remote Login. That should also remove it.

In my case, the “script” just retrieves the home page (html), causing a script error and a lot of wasted resources on every page view. Similar complaints in Does Domain Mapping plugin insert javascript on headers?.