I don't think it's "junk", it might be an image or a binary file

In general you should not be recording this type of requests, if you use Recording Template it will automatically filter images

So I would recommend filtering this kind of requests and instead configure HTTP Request Defaults to download embedded resources:

This way you will get browser-like behaviour of your JMeter test. See JMeter Web Testing: How To Properly Handle Embedded Resources in HTML Responses article for more information on how to properly deal with images, scripts, styles, fonts, etc.