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Category: Malware

Type: -

Aliases: Sasser.C, Worm.Win32.Sasser.c, W32/Sasser.C


Sasser.C is an Internet worm spreading through the MS04-011 (LSASS) vulnerability.


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 "avserve2.exe" process, then delete the file AVSERVE2.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

Sasser.C is a variant of Sasser.B, with identical length. Main difference is that this version starts 1024 processes to scan for new vulnerable hosts, instead of 128 processes.

For more details, see the description of Sasser.B