Sounds like you have Malware on your PC and a Key Logger program. Maybe a good Anti-Virus would help clean it up. Might also need a good Pro shop to check things.
You might download your blog by going to your Dashboard and performing an export under Tools > Export, so you have all of your content safe on your own computer
Good suggestion BUT - that only saves the text and links to Media (pictures & uploaded files) not the media files themselves -
Another good way to keep a backup is to have a friend do a backup for you - you do the export file - then using the old fashioned "sneaker net" hand carry the backup XML file on a CD to them - DO NOT EMAIL them about this, DO NOT CALL them using your cell phone or any of your regular phones (borrow a neighbors phone). Have them set up a new account and blog here - then import your blog to their new blog (include the media) - then set the new backup blog to "Private" so nobody can see it (including you) - leave no tracks!!!
that gives you a backup with the media - do not admit to anyone if you do this unless you are sitting across the table from them in a noisy area - if you are being censored by someone this will at least make them work harder.
Good luck and sorry for the extra drama
@Jackie - this is another time where the ability for the OP to download all their media to their PC and burn it to a CD would be very very good - a suggestion I made a few weeks ago - please put another check mark on the "would really help" sheet