LSASS Exploit E2K Attack blocked?

-So today and yesterday, Avast! has begun showing this message a few times a day.

I have done abit of research, but would like to know if i should be worried that it sometime might slip through. Is there a way to stop the attacks? Should i be worried? And what could happen if it does go through Avast! ?



Im using Avast! 4, Windows Vista and i am currently using dial-up internet from swedish Comviq as i am on vacation in said country.