lsass.exe is part of the security system that comes along with Microsoft Windows. The task of lsass.exe is to verify the validity of users when they log onto the PC.
By ending the lsass process you may encounter some difficulties when using Windows.
However lsass.exe may sometimes be a trojan horse or downloader disguised to look like an innocent process.
The lsass.exe file is located in the System32 folder, or C:\Windows\System32. If it is located anywhere else on the hard drive or computer, it is not a legitimate program and should immediately be deleted or quaratined. You should never delete or tamper with the file if it is located in the system32 directory.
The only way to determine whether the lsass.exe running is legitimate is to run a full scan of the computer.