W32/Sdbot-ZI

Please follow the instructions for removing worms.

W32/Sdbot-ZI is a worm and IRC backdoor Trojan for the Windows platform.

W32/Sdbot-ZI spreads by exploiting the following operationg system vulnerabilities:

LSASS (MS04-011)
RPC-DCOM (MS04-012)
WKS (MS03-049) (CAN-2003-0812)
MSSQL (MS02-039) (CAN-2002-0649)

W32/Sdbot-ZI runs continuously in the background, providing a backdoor server which allows a remote intruder to gain access and control over the computer via IRC channels.

When first run W32/Sdbot-ZI copies itself to <System>\nawadll32.exe.

The following registry entries are created to run nawadll32.exe on startup:

HKCU\Software\Microsoft\Windows\CurrentVersion\Run
nawadll32
nawadll32.exe

HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
nawadll32
nawadll32.exe

HKCU\Software\Microsoft\Windows\CurrentVersion\RunServices
nawadll32
nawadll32.exe

HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\RunServices
nawadll32
nawadll32.exe

W32/Sdbot-ZI sets the following registry entries, disabling the automatic startup of other software:

HKLM\SYSTEM\CurrentControlSet\Services\SharedAccess
Start
4

HKLM\SYSTEM\CurrentControlSet\Services\wuauserv
Start
4

Registry entries are set as follows:

HKCU\SYSTEM\CurrentControlSet\Control\Lsa
nawadll32
nawadll32.exe

HKLM\SYSTEM\CurrentControlSet\Control\Lsa
nawadll32
nawadll32.exe

HKCU\Software\Microsoft\OLE
nawadll32
nawadll32.exe

HKLM\SOFTWARE\Microsoft\Ole
nawadll32
nawadll32.exe

HKLM\SOFTWARE\Microsoft\Ole
EnableDCOM
N

HKLM\SYSTEM\CurrentControlSet\Control\Lsa
restrictanonymous
1

The following patches for the operating system vulnerability exploited by W32/Sdbot-ZI can be obtained from the Microsoft website:

LSASS (MS04-011) security vulnerability

RPC-DCOM (MS04-012) security vulnerability

MSSQL (MS02-039) (CAN-2002-0649) security vulnerability

WKS (MS03-049) (CAN-2003-0812) security vulnerability