If you run your blog using wordpress software, then please be aware that there is a wordpress worm going around, that can
This particular worm, like many before it, is clever: it registers a user, uses a security bug (fixed earlier in the year) to allow evaluated code to be executed through the permalink structure, makes itself an admin, then uses JavaScript to hide itself when you look at users page, attempts to clean up after itself, then goes quiet so you never notice while it inserts hidden spam and malware into your old posts.
Holy cow, who thinks up this stuff…
Check if your blog is infected.
Upgrade your blog software to wordpress 2.8.4, which takes care of the vulnarabilities that this worm exploits.
