Today there are reports of attack on self-hosted wordpress blog sites. If you are hosting your own blog on your own domain name, you must immediately upgrade your blog to WordPress 2.8.4 which is the latest version of WordPress.
This was first reported on Lorelle on WordPress.
How do you Find Out if Your WordPress Blog is Hacked?
According to Lorelle, you can check for the following:
There are two clues that your WordPress site has been attacked.
There are strange additions to the pretty permalinks, such as example.com/category/post-title/%&(%7B$%7Beval(base64_decode($_SERVER%5BHTTP_REFERER%5D))%7D%7D|.+)&%/. The keywords are “eval” and “base64_decode.”
The second clue is that a “back door” was created by a “hidden” Administrator. Check your site users for “Administrator (2)” or a name you do not recognize. You will probably be unable to access that account.
I would advice you to check your blog immediately for any strange activity and upgrade it to the latest WordPress version. It is a long weekend for me and for many of you, you wouldn’t want to spend all your time reviving your blog.
Before you click the “upgrade now” button in your WordPress DashBoard, please make sure to backup the files and also export the data using WordPress to an xml file. This will allow you to revive your blog in case something goes wrong during the upgrade process.
I would recommend you have a regular schedule, like weekly, to export the data from your WordPress Blog.
I hope you got this information before your blog is compromised.