Threat Description



Category: Malware
Platform: W32
Aliases: Sasser.D, W32/Sasser.D


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


Automatic action

Once detected, the F-Secure security product will automatically disinfect the suspect file by either deleting it or renaming it.

More scanning & removal options

More information on scanning or removal options is available in the documentation for your F-Secure security product on the Downloads section of our Home - Global site.

You may also refer to the Knowledge Base on the F-Secure Community site for further assistance.

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 "skynetave.exe" process, then delete the file 'skynetave.exe' from your Windows directory and reboot.

For step-by-step instructions, see Microsoft's site:

Technical Details

Sasser.D is a variant of Sasser.C. This version starts 128 processes to scan for new vulnerable hosts and sends ICMP ECHO requests before attacking.

For more details, see the description of Sasser.B.


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