W32/Sasser-G

Please follow the instructions for removing worms.

Windows NT/2000/XP/2003

In Windows NT/2000/XP/2003 you will also need to edit the following registry entry. The removal of this entry is optional in Windows 95/98/Me. Please read the warning about editing the registry.

At the taskbar, click Start|Run. Type 'Regedit' and press Return. The registry editor opens.

Before you edit the registry, you should make a backup. On the 'Registry' menu, click 'Export Registry File'. In the 'Export range' panel, click 'All', then save your registry as Backup.

Locate the HKEY_LOCAL_MACHINE entry:

HKLM\Software\Microsoft\Windows\CurrentVersion\Run\
avserve3 = avserve3.exe

and delete it if it exists.

Close the registry editor.

W32/Sasser-G is a network worm which spreads by exploiting a Microsoft LSASS vulnerability.

W32/Sasser-G also creates and executes SKYNET.CPL in the Windows folder which is detected by Sophos as W32/NetSky-AC. W32/Sasser-G is a network worm which spreads by exploiting a Microsoft LSASS vulnerability.

The worm copies itself to the Windows folder as AVSERVE3.EXE and sets the following registry entry to auto-start on user logon:

HKLM\Software\Microsoft\Windows\CurrentVersion\Run\
avserve3 = avserve3.exe

W32/Sasser-G attempts to connect to random IP addresses on ports TCP/445 and TCP/9996 and then exploit the LSASS vulnerability. If successful an FTP script is uploaded to and executed on the remote computer which connects back on port 5554 to download a copy of the worm via FTP.

W32/Sasser-G may cause the program LSASS.EXE to terminate which generally prompts Windows to shutdown and reboot. However, W32/Sasser-G attempts to prevent a system shutdown.

W32/Sasser-G also creates and executes SKYNET.CPL in the Windows folder which is detected by Sophos as W32/NetSky-AC.