What is the attacking mechanism of RF on IgG?
RF factors comprise antibodies that your body makes that exhibit auto-immunity (recognition of self as an antigen). They often recognize and bind to IgG antibodies as illustrated in this picture:


So the answer to your first question is that the underlying mechanism is inappropriate recognition of self from your immune system.

For your second question, I am not an expert in the type of chemical bonds employed by antibody-antigen interactions, so I looked it up briefly. This article was quite informative for that: Antibody/Antigen Complexes.  The majority of binding seems to be hydrogen and ionic binding. 

Hope that gets you going in your own searches.