W32/Rbot-GCJ

Please follow the instructions for removing worms.

W32/Rbot-GCJ is a worm with IRC backdoor functionality for the Windows platform.

W32/Rbot-GCJ spreads to other network computers by exploiting common buffer overflow vulnerabilities, including: LSASS (MS04-011), SRVSVC (MS06-040), RPC-DCOM (MS04-012) and ASN.1 (MS04-007).

W32/Rbot-GCJ 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-GCJ copies itself to \ctfmom.exe.

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

HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
Windows Update Firewall System
ctfmom.exe

HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\RunServices
Windows Update Firewall System
ctfmom.exe

The following registry entry is set, affecting internet security:

HKLM\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\ StandardProfile\AuthorizedApplications\List
|
|:*:Enabled:Windows Update Firewall System

W32/Rbot-GCJ 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
Windows Update Firewall System
ctfmom.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