Radek Mezulanik

This contact form contains Google reCaptcha as requirement. You can choose to accept attachment or not. 
If you use Classic editor, you will have a button for shortcode here.
Possible shortcodes:
<ol>
<li>
[contact]
</li>
<li>
[contact email=”yourmail@example.com” subject=”Your subject”]
</li>
<li>
[contact email=”yourmail@example.com”]
</li>
<li>
[contact subject=”Your subject”]
</li>
</ol>

Zedna Contact form

Contact from with attachments and reCaptcha in shortcode.

Sergey Biryukov

Allows to find all posts where a particular attachment (image, video, etc.) is used.
Adds a “Used In” column to the list view in Media Library, as well as to the attachment details modal.
Finds posts that use the image (including any of its intermediate sizes) in post content, or as a featured image. Works with custom post types too.
Inspired by a <a href="http://wptavern.com/the-problem-with-image-attachments-in-wordpress" rel="nofollow ugc">WP Tavern post</a> on image attachments.

Find Posts Using Attachment

Allows to find all posts where a particular attachment is used.

Zedna Contact form vs Find Posts Using Attachment