What is lsasss.exe?

The .exe extension on a filename indicates an executable file. Executable files may, in some cases, harm your computer. Therefore, please read below to decide for yourself whether the lsasss.exe on your computer is a Trojan that you should remove, or whether it is a file belonging to the Windows operating system or to a trusted application.

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Lsasss.exe file information

The process known as lsasss or Generic Host Process for Win32 Services belongs to software Microsoft® Windows (version 2000 Operating System) or Microsoft Windows Operating System by Microsoft (

Description: Lsasss.exe is not essential for Windows and will often cause problems. The lsasss.exe file is located in the C:\Windows\System32 folder. Known file sizes on Windows 10/8/7/XP are 37,859 bytes (3% of all occurrences), 37,163 bytes and 49 more variants. 
Lsasss.exe is not a Windows core file. There is no description of the program. The software starts upon Windows startup (see Registry key: MACHINE\Run). Lsasss.exe is able to monitor applications. Therefore the technical security rating is 53% dangerous, however you should also read the user reviews.

Recommended: Identify lsasss.exe related errors

If lsasss.exe is located in a subfolder of C:\, the security rating is 36% dangerous. The file size is 22,528 bytes. The program has a visible window. There is no file information. The application starts when Windows starts (see Registry key: MACHINE\Run). It is not a Windows core file.

External information from Paul Collins:

Important: Some malware also uses the file name lsasss.exe, for example W32.IRCBot.NG (detected by Symantec), and TROJ_SPNR.15AE14 (detected by TrendMicro). Therefore, you should check the lsasss.exe process on your PC to see if it is a threat. We recommend Security Task Manager for verifying your computer's security. This was one of the Top Download Picks of The Washington Post and PC World.


User Comments

i think its the sasser virus
its the sasser cause windows (system32) runs an exe file on startup call lsass.exe but the sasser names itself to lsasss.exe it has one additional s it is hididng because lsass.exe is a critical system process but i terminated lsasss.exe then deleted it first i went into safe mode but it is dangerous it opened like 120 backdoors in my computer and then duplicated itself to places the way to stop it is in the search type lsasss.exe if you find the one with 3 sss then deleted it.
I found it running alongside lsass.exe, when I terminated it there was no adverse effect.
This file is difficult to remove. it makes multiple copies and marks them hidden/readonly and changes names frequently. When my computer was infected, two virus/worms were packed together, sass as well as lsasss and the FyKu virus or some such. they multiply and hide themselves in the temp directory, attach themselves to Internet Explorer and Windows Explorer, as well as load themselves via the registry. They put little .bat files on the root directory too which all have to be deleted rapidly. Under windows 2000 you can do it from CtrlAltDel and ending as many processes as possible.
Not sure what it is exactly. But, I don't think its a virus. It does want to connect to the internet.
  Mike Knowles  
Local Security Authority Service - Windows process
Mind the difference between issas and Lsass - isass being dangerous and Lsass being a system process of the Microsoft Windows security mechanisms
Note the difference between lsass.exe and lsasss.exe, the latter being discussed here. The extra "s" does seem like someone wants this file to look like lsass.exe
lsass.exe is the Local Security Authencation SubSystem. Lsasss.exe is the sasser worm. The real lsass.exe has three s in it while the sasser worm look alike has four.
I got infect with lsasss and i cannot terminate it i can only terminate lsass app

Rating chart

Summary: Average user rating of lsasss.exe: based on 12 votes with 10 user comments. 2 users think lsasss.exe is essential for Windows or an installed application. One user suspects danger. 9 users think lsasss.exe is dangerous and recommend removing it. 2 users don't grade lsasss.exe ("not sure about it").

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Best practices for resolving lsasss issues

A clean and tidy computer is the key requirement for avoiding problems with lsasss. This means running a scan for malware, cleaning your hard drive using cleanmgr and sfc /scannow, uninstalling programs that you no longer need, checking for Autostart programs (using msconfig) and enabling Windows' Automatic Update. Always remember to perform periodic backups, or at least to set restore points.

Should you experience an actual problem, try to recall the last thing you did, or the last thing you installed before the problem appeared for the first time. Use the resmon command to identify the processes that are causing your problem. Even for serious problems, rather than reinstalling Windows, you are better off repairing of your installation or, for Windows 8 and later versions, executing the DISM.exe /Online /Cleanup-image /Restorehealth command. This allows you to repair the operating system without losing data.

To help you analyze the lsasss.exe process on your computer, the following programs have proven to be helpful: Security Task Manager displays all running Windows tasks, including embedded hidden processes, such as keyboard and browser monitoring or Autostart entries. A unique security risk rating indicates the likelihood of the process being potential spyware, malware or a Trojan. Malwarebytes Anti-Malware detects and removes sleeping spyware, adware, Trojans, keyloggers, malware and trackers from your hard drive.

Other processes

lsasss.exe [all]