W32/Rbot-AAB

Please follow the instructions for removing worms.

You will also need to edit the following registry entries, if they are 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

HKLM\Software\Microsoft\Windows\CurrentVersion\RunServices

and remove any reference to any file you deleted.

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

HKU\[code number]\Software\Microsoft\Windows\
CurrentVersion\Run\

and remove any reference to any file you deleted.

Close the registry editor.

Check the following items

• To renable DCOM you can edit the registry, but it's better to use Dcomcnfg.exe. See Microsoft article 825750 for details.
• The HKLM\SYSTEM\CurrentControlSet\Control\Lsa\restrictanonymous = "1" setting does not allow enumeration of SAM accounts and names. The default is "0". It can be changed in Local Security Policy. See Microsoft article 246261 for details.
• Check your administrator passwords and review network security.

W32/Rbot-AAB is an IRC backdoor Trojan and network worm.

W32/Rbot-AAB may spread to remote network shares protected by weak passwords and computers vulnerable to common exploits. The worm also opens up a backdoor, allowing unauthorised remote access to infected computers via the IRC network, while running in the background as a service process. The worm exploits the following vulnerabilities: WKS (MS03-49), RPC-DCOM(MS04-12) and LSASS (MS04-11). For patches for these vulnerabilities, see:

http://www.microsoft.com/technet/security/bulletin/MS04-011.mspx
http://www.microsoft.com/technet/security/bulletin/MS04-012.mspx
http://www.microsoft.com/technet/security/bulletin/MS03-049.mspx

W32/Rbot-AAB can receive commands from a remote intruder to delete network shares, log keypresses, participate in DDoS attacks, scan other computers for vulnerabilities, steal passwords, steal registration keys for computer games, create administrator accounts, terminate firewall and anti-virus processes and capture video from webcameras attached to the computer.

W32/Rbot-AAB copies itself to the Windows system folder as xpiupdate.exe and creates the following registry entries in order to run automatically on computer login:

HKLM\Software\Microsoft\Windows\CurrentVersion\Run
xpiupdate
xpiupdate.exe

HKLM\Software\Microsoft\Windows\CurrentVersion\RunServices
xpiupdate
xpiupdate.exe

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

The worm also hardens the computer against further attack by setting the following registry entries:

HKLM\SOFTWARE\Microsoft\Ole
EnableDCOM
N

HKLM\SYSTEM\CurrentControlSet\Control\Lsa
restrictanonymous
1