Google Webmaster Tools - Invalid urls being added as 404

[barney]

I was lookng thru my webmaster tools for my website and I notice when I go to diagnostics and web crawl
I see a bunch of 404 (not found) errors and they all have my website http://www.example.com/trace.php?url=something but I don't even have that php file in my website nor have I ever did.

Know what might have caused this error to appear on webmaster tools? Any solutions of fixing this and/or should i have that trace.php go to my homepage?

[edited by: tedster at 6:57 pm (utc) on Dec. 15, 2007]
[edit reason] switch to example.com - it can never be owned [/edit]

[tedster]

Many people have seen this kind of thing, and if you don't have that url on your site then it SHOULD return a 404. Don't take steps trying to make it resolve, let it stay 404.

The question of where googlebot gets this url is pretty much irrelevant, unless somehow it is accidentally in the source code for one of your pages. You can run a tool like Xenu Link Sleuth on your domain just to be sure. You might have some kind of error somewhere that created the url by accident, or someone might have hacked your server.

But this kind of thing does happen, and tracking down the "why" of it can be both frustrating and futile. Just make 100% sure that character string does not appear in your site's source code, and then forget about it.

[g1smd]

Sometimes those fake URLs are just caused by links from some other site where the person has mistyped the URL they actually wanted to include.