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Virus Encyclopedia

Welcome to the Virus Encyclopedia of Panda Security.


Threat LevelModerate threatDamageHighDistributionNot widespread
Common name:Sasser.D
Technical name:W32/Sasser.D.worm
Threat level:Low

It restarts the computer. It spreads by exploiting the LSASS vulnerability.

Affected platforms:

Windows 2003/XP/2000/NT/ME/98

First detected on:May 3, 2004
Detection updated on:Dec. 15, 2005
Proactive protection:
Yes, using TruPrevent Technologies
Repair utility:Panda QuickRemover

Brief Description 


Sasser.D is a worm that spreads via the Internet by exploiting the LSASS vulnerability in remote computers. This vulnerability is critical only for Windows XP/2000 operating systems that are not properly updated.

Sasser.D restarts the computer automatically when it attempts to exploit the already mentioned vulnerability.

Sasser.D only spreads automatically to Windows XP/2000 computers. However, computers with other Windows operating systems can also be a source of transmission when a malicious user runs the file containing the worm in any of these computers.

If you have a Windows 2003/XP/2000/NT computer, it is highly recommendable to download the security patches for the LSASS vulnerability from the Microsoft website.

Visible Symptoms 


Sasser.D is easy to recognize, as it restarts Windows XP/2000 computers when it attempts to affect this computer by exploiting the LSASS vulnerability. When this action is carried out, Sasser.D displays the following message on screen: