Im having this weird problem in magento, when i try to log in the admin i was seeing this
The requested URL /js/js.php was not found on this server.
Apache Server at example.co.uk Port 80
This is malware, remove it from your site! Take your site offline. Change FTP/user passwords and perform a malware scan of your files.
check your first lines in index.php in the root. In my case there was something placed by eclipse. Something like $x15='http://boatandyachtbuyer.co.uk'
I have deleted all these strange variables. Works like a charm.
Hope it helps.