Lsass.exe is vital for the operation of Windows.
Lsass.exe is LSA Shell (Export Version). LSA = Local Security Authority.
It is also called the Local Security Administration Subsystem Service.
Lsass.exe seems to have a lot of names.
Lsass.exe starts pretty early in the Windows boot process.
Lsass.exe runs all of the time and is one of the few processes that cannot
be ended with Task Manager.
Lsass.exe is a system process of the Microsoft Windows security mechanisms.
It specifically deals with local security and login policies.
Lsass.exe is the local security authentication server, and 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.
Lsass.exe is responsible for many services: Net Logon (netlogon), NT LM
Security Support Provider (NtLmSsp), IPSEC Services (PolicyAgent), Protected
Storage (ProtectedStorage) and Security Accounts Manager (SamSs).
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Npfs\Aliases
Value Name: lsass
Data Type: REG_MULTI_SZ
Value Data: protected_storage;netlogon;lsarpc;samr
The Security Account Manager Remote Procedure Call (RPC) protocol (SAMR) is
an integral subsystem that is used to perform remote Service Account Manager
operations, such as user account management and manipulation. The SAMR
interface defines the remote Security Account Manager (SAM) methods that are
called by the client.
Netlogon – Net Logon service
Lsarpc – LSA access
Samr – SAM access
When Windows boots, the MBR(Master Boot Record) reads the boot sector which
is the first sector of the active partition. This sector contains the code
that starts Ntldr which is the boot strap loader for Windows XP. Ntldr runs
Ntdetect.com to get information about installed hardware. Ntldr, then,
loads the two files that make up the core of XP: Ntoskrnl.exe and Hal.dll.
Ntoskrnl.exe starts Winlogon.exe which starts Lsass.exe (Local Security
Administration), this is the program that displays the Welcome screen and
allows a user to log on with their credentials (user name and password).
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Hope this helps. Let us know.
Wes
MS-MVP Windows Shell/User
In