Oipjuss on "wp-includes/Text/Diff/.log files with misleading names"

Hello,

In a subdir on the server (wp-includes/Text/Diff/.log) i find a map with about 3500 html-files with misleading names. For i can see these files have nothing to do with my site. Therefor i'm afraid that some malicious stuff has find his way on my site.
What can i do now? How to clean up my site from unwanted content or how can i scan my site en clean it up?
The date's of these files are going back to 1 october 2013.

Thanks in advance.
With regards,
Oipjuss