W32.Sasser.G 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. The worm’s function is identical to that of W32.Sasser.E.Worm, but W32.Sasser.G contains an extra PE file section, which is 1 byte in size and appears to have no function. W32.Sasser.G 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.G 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.G can run on, but not infect, Windows 95/98_* Stephan123 computers. Although these operating systems cannot be infected, they can still be used to infect vulnerable computers._
Info http://securityresponse.symantec.com/avcenter/venc/data/w32.sasser.g.htm
Has avast already a update for itl