Regarding the previous post—something was rotten, and the baddies were coming from Mother Russia, admittedly. All the evidence pointed to a compromised 3rd party captcha mechanism, so I wiped it off.
I also moved the blog database to a fresh install of Movable Type 4.2.1—the basic functions are working, but there are some glitches left and a few features unimplemented yet. For instance, the blog roll is missing for now, the comment preview is borked and so on. Sorry about that.
Please bear with me a couple of days until I have a chance to iron out the remaining issues and also please let me know if you encounter anything suspicious. Thank you for your indulgence.
Update 1: Blogroll is slowly coming back. Comments mechanism still broken and not much time to get to the bottom of it. Thanks for patience.
Update 2: Comments working again. Upgrade done. Situation back to normal.