Spam injection hack: Upgrade and tighten WP now!

[Ms Naughty]

I'm not sure if it's the same thing. I went from no comments at all to 30 in one hour, all with multiple links... it just took a while for me to work out that something wasn't right.

To fix the db you need to browse through wp_options. Right down the bottom you might find an active_plugin (or in my case, deactivated_plugin) with a name like:
a:1:{s:5:./././././././././././././././././././././tmp/upl52653.jpg

Delete it.

The you might want to go back and activate your plugins one by one to see if the posting process works.

Not sure if it's always the same file, but it may be something similar.

Anyway, this is the topic to read:
http://wordpress.org/support/topic/154571?replies=19