W32/Rbot-GK

Please follow the instructions for removing worms.

You will also need to edit the following registry entries, if present. 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 entries:

HKLM\Software\Microsoft\Windows\CurrentVersion\Run\
Microsoft Update Machine = winhost.exe
HKLM\Software\Microsoft\Windows\CurrentVersion\RunServices\
Microsoft Update Machine = winhost.exe

and delete them if they exist.

Each user has a registry area named HKEY_USERS\[code number indicating user]\. For each user locate the entry:

HKCU\[code number]\Software\Microsoft\Windows\CurrentVersion\Run\
Microsoft Update Machine = winhost.exe

and delete it if it exists.

Close the registry editor.

• Check your administrator passwords and review network security.
• Download and install the Microsoft patches mentioned. On standalone computers, update with all relevant security patches from Windows update.

W32/Rbot-GK is a network worm and backdoor Trojan for the Windows platform. W32/Rbot-GK allows a malicious user remote access to an infected computer.

The worm copies itself to a file named winhost.exe in the Windows system folder and creates the following registry entries:

HKLM\Software\Microsoft\Windows\CurrentVersion\Run\
Microsoft Update Machine = winhost.exe
HKLM\Software\Microsoft\Windows\CurrentVersion\RunServices\
Microsoft Update Machine = winhost.exe
HKCU\Software\Microsoft\Windows\CurrentVersion\Run\
Microsoft Update Machine = winhost.exe

W32/Rbot-GK spreads using a variety of techniques including exploiting weak password on computers and SQL servers, exploiting operating system vulnerabilites (including DCOM-RPC, LSASS, WebDAV and UPNP) and using backdoors opened by other worms or Trojans.

W32/Rbot-GK can be controlled by a remote attacker over IRC channels.

Patches for the operating system vulnerabilities exploited by W32/Rbot-GK can be obtained from Microsoft at:
MS04-011, MS03-026, MS03-007 and MS01-059.