The lsass.exe process is included with Microsoft Windows and works to enforce the security policy on your system. It is responsible for verification when a user logs in, their password, and also access tokens to allow or prevent a user from accessing specific files or locations on the system. The process is also responsible for writing to the Windows Security Log.

If this file is ever stopped, your machine will need to be rebooted to resume normal system function.

File name: Lsass.exe
Application: Local Security Authority Subsystem Service
Publisher: Microsoft
Rating: 4 stars based on 434 votes
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Possible causes of Lsass.exe errors

These errors are frequently caused by conflicts with the file or installation profile, misuse of the file or respective directories, or a malicious attack on the system.

  • When conflicts arise on the profile or with the file, the application may be unable to transmit data between the necessary files.
  • When a file or directory is misused or damaged, the application as a whole may be unable to load.
  • Malicious attacks or infections on the system may render the entire system frozen or unable to perform any necessary computing functions.
Regardless of the cause, determining the best solution should be the first action step when noticing any system-related computer errors.

Is Lsass.exe a dangerous file (virus, malware, spyware)?

In most cases, the file is considered to be safe. However, files do become corrupt at times and some malicious files are disguised to represent known, secure system files. When that happens, they can be very difficult to detect and remove, but using a comprehensive system scan usually detects them and allows you to safely remove them.

Known Lsass.exe error messages

Lsass.exe error

Common error messages users may see include:

  • File not found: Lsass.exe
  • Cannot find file: Lsass.exe
  • Device not recognized missing Lsass.exe file
As the file is associated with USB connections to the computer, a keyboard, mouse, or other piece of hardware connected to the machine through a USB cable may be causing the error or may be unable to function properly due to the error.

Should I stop the Lsass.exe task or process within the Task Manager?

Unless you have experience managing the processes and tasks on your machine, it is best to allow a system scanner or registry scanner to handle those tasks. Many of the tasks are required for performing specific operations on your machine and removing them may cause your program or entire computer to malfunction or reboot.

Should I download a new copy of the Lsass.exe file?

The only time you should ever download a new version of a system file is when it comes through an application update or from the publisher directly. Be very cautious when downloading system files from third-party websites as they may contain additional software that you would install without knowing. This could cause an even larger issue than the error you are getting from this file!
WARNING: If you already downloaded a new file from an external site,
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Best way to fix Lsass.exe errors

When these errors occur, verify if any new hardware or software has been added. If so, simply removing the new hardware or software may resolve the issue. If not, follow the steps below.

  1. Scan for any driver updates for new equipment. If new equipment or programs have been loaded, they may require updated drivers. Download new, secure drivers and perform a clean system restart.
  2. Download and install updates for the operating system. Regardless of the operating system version you are using, it is always considered good practice to install the latest security updates.
  3. Use anti-virus and anti-malware applications. Most virus scanners will protect your machine from basic threats. To increase your protection, use a malware scanner as well.
If the above steps fail to resolve the issue, it may be due to outdated hardware or software.

More information about Lsass.exe

Due to the popularity of this file and the fact that it is installed on Microsoft Windows, some malicious developers have used this same file name to hide viruses to infect unsuspecting users. If you notice this file outside of your primary system directory, you may want to verify the integrity of it and perform the necessary steps to scan your system and prevent additional security flaws or damages from happening to your system.

Some malicious file names to be aware of include lsas.exe, Isass.exe (capital "i" instead of a lowercase "L"), lsassexe.exe, and other files with similar misspellings.

Unfortunately, this file has been known to show signs of malware. Due to this, it can cause errors with related system files as well. One system file that may display errors in conjunction with this one is winlogon.exe. If you begin noticing errors with these files together, your system might be in critical danger. If you are noticing errors with one file or the other, you may still be under attack and you should take the necessary steps to prevent any further risk.