Adbull and POST reading?

So I just came across an annoying ad from a group that pops up under your mouse and follows it around the screen.
I added it to the Opera block list and it didn't go away, SO I went to my google search bar and typed "Adbull block". Didn't connect to server.
So I go to Google.com and type the exact same thing into it. Google doesn't even do anything. Try typing something random, and it goes through. So I try Bing. "Adbull block" doesn't go through. Same for Wisenut.
I wonder what the heck this thing is actually doing that it can monitor your POST data and prevent it from being sent? It persists even after closing the tab and even the browser.

Note: This isn't a malware removal problem for me, as I'm running Returnil and can just restore. I'm just curious how this is even possible.

 

some badware is running that does it.