W32/Rbot-BCB

Please follow the instructions for removing worms.

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

W32/Rbot-BCB spreads to other network computers by exploiting common buffer overflow vulnerabilities, including: RPC-DCOM (MS04-012), WKS (MS03-049) (CAN-2003-0812) and ASN.1 (MS04-007) and by copying itself to network shares protected by weak passwords.

W32/Rbot-BCB 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-BCB copies itself to <Windows folder>\alg.exe.

The file alg.exe is registered as a new system driver service named "AppGateway", with a display name of "AppGateway" and a startup type of automatic, so that it is started automatically during system startup. Registry entries are created under:

HKLM\SYSTEM\CurrentControlSet\Services\AppGateway\

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

HKLM\SYSTEM\CurrentControlSet\Services\Messenger
Start
4

HKLM\SYSTEM\CurrentControlSet\Services\RemoteRegistry
Start
4

HKLM\SYSTEM\CurrentControlSet\Services\TlntSvr
Start
4

Registry entries are set as follows:

HKLM\SOFTWARE\Policies\Microsoft\Windows\WindowsUpdate
DoNotAllowXPSP2
1

HKLM\SOFTWARE\Microsoft\Ole
EnableDCOM
N

HKLM\SYSTEM\CurrentControlSet\Control\Lsa
restrictanonymous
1

Registry entries are created under:

HKLM\SOFTWARE\Microsoft\Security Center\
HKLM\SOFTWARE\Policies\Microsoft\WindowsFirewall\DomainProfile\
HKLM\SOFTWARE\Policies\Microsoft\WindowsFirewall\StandardProfile\

Patches for the operating system vulnerabilities exploited by W32/Rbot-BCB are available from Microsoft:
MS03-049
MS04-007
MS04-012