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Category: Malware

Type: -

Aliases: Sasser.E, W32/Sasser.E, LSASSS


Sasser.E is an Internet worm spreading through the MS04-011 (LSASS) vulnerability.Sasser.E is a variant of Sasser.D.


Automatic action

Once detected, the F-Secure security product will automatically handle a harmful program or file by either deleting or renaming it.

Eliminating a Local Network Outbreak

If the infection is in a local network, please follow the instructions on this webpage:

Manual Disinfection

To manually disinfect an infected system, first apply the Microsoft patch MS04-011, then use Task Manager to kill the "lsasss.exe" process, then delete the file 'lsasss.exe' from your Windows directory and reboot.

For step-by-step instructions, see Microsoft's site: https://www.microsoft.com/security/incident/sasser.asp#steps

Knowledge Base

Find the latest advice in our Community Knowledge Base.

About the product

See the manual for your F-Secure product on the Help Center.

Contact Support

Chat with or call an expert for help.

Submit a sample

Submit a file or URL for further analysis.

Technical Details

It has been modified by changing the main virus file name to LSASSS.EXE. Note that this has nothing to do with Windows' LSASS.EXE. Also the port numbers used for the shell and FTP server have been changed.

Also, Sasser.E tries to remove the Bagle worm, unlike earlier Sassers but just like many Netsky variants.

Two hours after infection Sasser.E displays the following message:

For more details on Sasser, see description of Sasser.D.