I'm working on a local WordPress site, and for some reason there is an iframe added just after the opening body tag which makes the body to drop down about 20px.

Google only returned 1 relevant result when searching for it, and what I read there didn't help much. It can be found here.

The WordPress site has no plugins installed, and setting it to display: none; doesn't work.

Here's a screenshot from Chrome so you can see it: