W32.Sasser.E.Worm

W32.Sasser.E.Worm is a minor variant of W32.Sasser.Worm. It attempts to exploit the LSASS vulnerability, described in Microsoft Security Bulletin MS04-011, and spreads by scanning randomly selected IP addresses for vulnerable systems.

W32.Sasser.E.Worm differs from W32.Sasser.Worm as follows:

• Uses a different mutex: SkynetNotice.
• Uses a different file name: lsasss.exe.
• Creates a different value in the registry: "lsasss.exe"
• Uses different port numbers, used by FTP server and the remote shell: 1023 and 1022.
• After 2 hours of running it displays a message.
• It deletes the values from the registry, which are known to be installed by Trojan.Mitglieder, W32.Beagle.W@mm, and W32.Beagle.X@mm.
• The name of the file retrieved from the FTP server is followed by _update.exe.
• The worm logs data into the file C:\ftplog.txt.
• Has an updated routine for finding vulnerable computers. W32.Sasser.E.Worm sends an ICMP echo request before attempting to make a connection. This change may prevent the worm from properly executing on Windows 2000 systems.

W32.Sasser.E.Worm can run on, but not infect, Windows 95/98/Me computers. Although these operating systems cannot be infected, they can still be used to infect vulnerable computers.

Protection

• Initial Rapid Release version May 9, 2004
• Latest Rapid Release version July 19, 2008 revision 019
• Initial Daily Certified version May 9, 2004
• Latest Daily Certified version July 19, 2008 revision 018
• Initial Weekly Certified release date May 9, 2004

Click here for a more detailed description of Rapid Release and Daily Certified virus definitions.

Threat Assessment

Wild

• Wild Level: Low
• Number of Infections: 50 - 999
• Number of Sites: More than 10
• Geographical Distribution: Low
• Threat Containment: Easy
• Removal: Moderate

Damage

• Damage Level: Low

Distribution

• Distribution Level: High