Immediately after reboot my browser started to work slowly, lots of additional toolbars appeared together with new directories in favorites and six! new icons on desktop (all done without any question). Then Internet ads started to appear at random.
It took forty minutes to clear this crap out. Partially by manual registry cleansing, partially by uninstall program hidden on site of plugin authors. Most probably to avoid lawsuits.
Moral of the story:
1) Regardless of how much you want ANY file under ANY plugin - click no.
2) Never ever use Internet ads in your business unless you KNOW EXACTLY where and how they will be posted