W32/Rbot-BAJ

Please follow the instructions for removing worms.

W32/Rbot-BAJ is a worm and IRC backdoor for the Windows platform.

W32/Rbot-BAJ spreads to other network computers by exploiting common buffer overflow vulnerabilities, including: LSASS (MS04-011), RPC-DCOM (MS04-012) and MSSQL (MS02-039) (CAN-2002-0649) and by copying itself to network shares protected by weak passwords.

W32/Rbot-BAJ 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/Rbot-BAJ copies itself to <Windows system folder>\enzxp.exe.

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

HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
Registry Value Name
enzxp.exe

HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\RunServices
Registry Value Name
enzxp.exe

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

HKLM\SYSTEM\CurrentControlSet\Services\wuauserv
Start
4

HKLM\SYSTEM\CurrentControlSet\Services\SharedAccess
Start
4

Note: disabling autostart for the SharedAccess service deactivates the
Microsoft Internet Connection Firewall (ICF).

Registry entries are set as follows:

HKCU\Software\Microsoft\OLE
Registry Value Name
enzxp.exe

HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings
MaxConnectionsPer1_0Server
50

HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings
MaxConnectionsPerServer
50

HKLM\SOFTWARE\Microsoft\Ole
EnableDCOM
N

HKLM\SYSTEM\CurrentControlSet\Control\Lsa
restrictanonymous
1

The following patches for the operating system vulnerabilities exploited by W32/Rbot-BAJ are available from Microsoft
MS04-012
MS04-011
MS02-039