If you use WordPress to run your blog, you should check to make sure you’re not running version 2.1.1, which was compromised by a cracker who gained access to a WordPress server and tampered with the download file. The WordPress folks have released a newer version (2.1.2) that is safe to use. If you are running 2.1.1., you should upgrade to 2.1.2 immediately.
Source: CNET.com’s Security Bites! podcast