Solution to a 404 problem with wordpress

Every page shows the 404-message today. We did not do anything on the site that could have caused this. I thought that it was a plugin that had broken, cause I could not even access the plugins page in the dashboard. I tried to disable every plugin by changing their names via a ftp-client, but that did not help. Then I checked the .htaccess files and saw something odd:

/tmp/25454b22bf39c75795851f39d5e347c4

There were two lines at the bottom of the file that said the following:

AddType application/x-httpd-php .php .phtml .php3 .php4 .php5 .htm .html

php_value auto_prepend_file /tmp/25454b22bf39c75795851f39d5e347c4

Remove these two lines, and everything will work again! Even if you have no .htaccess files in your folders, check again, because there are one now. There were a hack January 24, 2010 that caused this on a lot of sites over the world! In a lot of folders containing php files, there is now also a .htaccess file with these two lines, making your site only show the 404 page. Not only on WordPress sites, I found at least one OsCommerse site that had been hacked the same way here! I contacted my web host for asking if they knew where this came from, but they were still searching. I will put an update if they find out where this came from.

But until that, write in the comment field if you know what it is about, and remove the lines or the .htaccess file so that the page works again.