Facebook and Hijackers

Hey everyone, i have a friend on Facebook that seems to have some type of Hijacker take over. It seems to be posting links to many other friends pages without her knowledge. It always goes something like "(the link) helped me knock out 8lbs in 8 days". I have seen many others all through Facebook like "I won a free Ipod, here is how i did it. (link)".

First off i know Facebook can also be a rather risky site as i have read of different viruses being spread on it. I know better than to click on links that are strange or sound too good to be true. I stay away from Farmville and all the other games and apps that need access to your information to be able to run.

I would like to learn a little bit about what this might be and how to get rid of it so that i may be able to direct her on what to do.

I'm guessing there may have been some talk about things like these on this forum but my searches all bring up non relevant information. Anybody know much about this?

Thanks, Jerry.