Unrecognised Files Scanner summary
Shield Security plugin is composed of several parts (modules). Hack Guard is one of its modules.
Hack Guard is composed of various components (features). The Automatic WordPress File Scanner is one of its features. The Unrecognised Files Scanner is a part of the Automatic WordPress File Scanner.
How does the Unrecognised File Scanner work?
What are the Unrecognised files?
Unrecognised files are the files that are not part of your WordPress core installation.
In other words, all non-standard files stored inside the WordPress core installation are identified as unrecognised.
What Unrecognised files should be removed?
The Unrecognised File Scanner will detect Unrecognised files. These files can be reviewed under the Scans section > Scan Results of the Shield plugin. Then you decide whether to remove or to keep them.
Files that you want to keep can be ignored through Scan Results section.
If you need to exclude file or folder paths from scans, you can use Scan Exclusions option.
If you are still unsure which uncategorised files you should keep or remove, please talk to your web host and they'll help you determine what's best for your site.
To learn more about the Unrecognised Files Scanner, read our blog article here.
We also highly recommend you to read A Complete Guide To The Shield Security Scans here.