Alarming insertions in every post. Help!

If it is in your actual page content, you’ve been hacked and someone added that content to your pages.

If it’s in comments, use something like Akismet for some anti-spam

I dont think the pages have been attacked. Only blog posts. Is Akismet a workpress thingie?

Your site has been infected with SEO spam. Here’s where you will need to start for information on how to clean things up: FAQ My site was hacked ..And some info for after things are cleaned up that might help. Hardening WordPress