These files are generated by Microsoft's Ngen.exe program.
and
C:\WINDOWS\assembly\NativeImages_...
maybe, so I decided to look in my harddrive and looking around the "NativeImages"
Are you refering to .nl.dll files?
If its created by microsoft or stuff that came from withe manufacture of the computer then yes, if its a third party company then it needs to be checked out.
The files and sub-directories inside the “C:\WINDOWS\assembly\NativeImages_vx.y.z…” directories belong to the Microsoft .NET framework. These files can be considered safe.
I am very surprised that files NativeImage_…dll reappeared in the “File List” even though I deleted them from the list several weeks ago (for these files the “Jump to Folder” feature was either inactive or invisible).
For these “new files” the “Jump to Folder” feature is always inactive or invisible.
More surprising the “First Observed” date of these files is in December 2020.
When you use the Purge button CIS will remove all entries that point to files that are no longer on your hard drive. CIS will not automatically remove entries that point to file that are no longer on your hard drive.