It's just common spam. My spam changes every few weeks or so too. Just depends what the spammers change to make things work and get past the spam checkers.
Thunderbird has its own very capable spam filter. Any piece that you find to be spam should be marked as junk by highlighting it and clicking the junk button. If you know that your email server uses some spam software before it even reaches you, such as SpamAssassin, you can tell thunderbird that too in the settings and stuff marked as spam by the server will automatically go into your junk folder.
The spam filter in thunderbird is bayesian, meaning that it learns as you report spam. In the beginning it won't be that great, but after using it for a while (and make sure any nonspam it reports as spam you use the "not junk" button too), it'll pick up spam very well.