What is it?
Local Security Authentication Server - lsass.exe
What does it do? lsass.exe - It generates the process responsible for authenticating users for the
Winlogon service. This process is performed by using authentication
packages such as the default Msgina.dll. If authentication is
successful, Lsass generates the user's access token, which is used to
launch the initial shell. Other processes that the user initiates
inherit this token.
You will not be able to end this through task manager!
The lsass.exe which is from Microsoft is located at
c:\windows\System32\lsass.exe . there's a few viruses that have been found
to run as lsass.exe to hide from you.