I think you need a bit more information. You probably have a virus as it is seldom that the lssas. exe file becomes corrupt.
Process name: Local security authentication server
"lsass.exe" is the Local Security Authentication Server. It verifies the validity of user logons to your PC/Server. 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. More info
Note: The lsass.exe file is located in the C:\Windows\System32 folder. In other cases, lsass.exe is a virus, spyware, trojan or worm!
Virus with same name:
W32.Nimos.Worm - Symantec Corporation
W32.Sasser.E.Worm (Lsasss.exe) - McAfee
W32.HLLW.Lovgate.C@mm - Symantec Corporation
Heres Microsofts fix.http://www.microsoft...er_printxp.mspx
And a removal tool from Norton's.http://www.symantec....-050114-1706-99