Injected Script

Nope, it is nothing malicious. This is a base64 encoding method for image files that is designed to make them more efficient.
https://en.wikipedia.org/wiki/Data_URI_scheme

<img id="__kallout-sm-target-image" style="position: absolute; visibility: visible; color: transparent; margin: 0px; z-index: 2147483647; left: 492px; top: 289px;" src="data:image/png;base64,iVBORw0KGgo
...
...
...
QmCC" alt="">

Glad that it’s a false positive case, thanks BPS!

Oops, resolved!