check out the following site to know abt lsass
*www.neuber.com/taskmanager/process/lsass.exe.html
an exploit atack generates in avast every now and then"when some1 is trying to peek into your system, perhaps", you need not worry about it, just turn it off.
here you can find something more on lsass exploit
*www.esecurityplanet.com/alerts/article.php/3363201