Threat Explorer

The Threat Explorer is a comprehensive resource consumers can turn to for daily, accurate, up-to-date information on the latest threats, risks and vulnerabilities.

VBS.Netlog.I

VBS.Netlog.I

Discovered:
09 August 2001
Updated:
13 February 2007

VBS.Netlog.I is simple variant of VBS.Network . This worm attempts to map random IP addresses to drive R. If it is successful, it copies itself to the StartUp folder of the mapped drive.

Antivirus Protection Dates

  • Initial Rapid Release version 10 August 2001
  • Latest Rapid Release version 28 September 2010 revision 054
  • Initial Daily Certified version 10 August 2001
  • Latest Daily Certified version 28 September 2010 revision 036
  • Initial Weekly Certified release date pending
Click here for a more detailed description of Rapid Release and Daily Certified virus definitions.

This worm copies itself to the root of drive C as C:\Rainbow.vbs. It makes the following changes to the registry:
  • It sets the value data of the value

    Level

    to 1

    in the key

    HKEY_CURRENT_USER\Software\Microsoft\
    Office\9.0\Word\Security
  • It sets the value data of the value

    Installed

    to 1

    in the key

    HKEY_LOCAL_MACHINE\Software\Microsoft\
    Windows\CurrentVersion\Network
  • It adds the subkey

    Rainbow

    to the key

    HKEY_LOCAL_MACHINE\Software\Microsoft\
    Windows\CurrentVersion\Network\LanMan

    and sets its value to

    Path  C:\
  • It sets the value data of the value

    ComputerName

    to

    Rainbow

    in the key

    HKEY_LOCAL_MACHINE\System\CurrentControlSet\
    Services\VxD\VNETSUP
  • It sets the value data of the value

    FileSharing

    to

    Yes

    in the key

    HKEY_LOCAL_MACHINE\System\CurrentControlSet\
    Services\VxD\VNETSUP\FileSharing
  • It sets the value data of the value

    NeverShowExt

    to

    1

    in the key

    HKEY_CLASSES_ROOT\VBSFile\

The worm also keeps a log of the IP addresses of computers to which it copies itself. This is stored in the C:\Rainbow.txt file.

VBS.Netlog.I also deletes C:\Network.vbs if it exists.

Recommendations

Symantec Security Response encourages all users and administrators to adhere to the following basic security "best practices":

  • Use a firewall to block all incoming connections from the Internet to services that should not be publicly available. By default, you should deny all incoming connections and only allow services you explicitly want to offer to the outside world.
  • Enforce a password policy. Complex passwords make it difficult to crack password files on compromised computers. This helps to prevent or limit damage when a computer is compromised.
  • Ensure that programs and users of the computer use the lowest level of privileges necessary to complete a task. When prompted for a root or UAC password, ensure that the program asking for administration-level access is a legitimate application.
  • Disable AutoPlay to prevent the automatic launching of executable files on network and removable drives, and disconnect the drives when not required. If write access is not required, enable read-only mode if the option is available.
  • Turn off file sharing if not needed. If file sharing is required, use ACLs and password protection to limit access. Disable anonymous access to shared folders. Grant access only to user accounts with strong passwords to folders that must be shared.
  • Turn off and remove unnecessary services. By default, many operating systems install auxiliary services that are not critical. These services are avenues of attack. If they are removed, threats have less avenues of attack.
  • If a threat exploits one or more network services, disable, or block access to, those services until a patch is applied.
  • Always keep your patch levels up-to-date, especially on computers that host public services and are accessible through the firewall, such as HTTP, FTP, mail, and DNS services.
  • Configure your email server to block or remove email that contains file attachments that are commonly used to spread threats, such as .vbs, .bat, .exe, .pif and .scr files.
  • Isolate compromised computers quickly to prevent threats from spreading further. Perform a forensic analysis and restore the computers using trusted media.
  • Train employees not to open attachments unless they are expecting them. Also, do not execute software that is downloaded from the Internet unless it has been scanned for viruses. Simply visiting a compromised Web site can cause infection if certain browser vulnerabilities are not patched.
  • If Bluetooth is not required for mobile devices, it should be turned off. If you require its use, ensure that the device's visibility is set to "Hidden" so that it cannot be scanned by other Bluetooth devices. If device pairing must be used, ensure that all devices are set to "Unauthorized", requiring authorization for each connection request. Do not accept applications that are unsigned or sent from unknown sources.
  • For further information on the terms used in this document, please refer to the Security Response glossary.

To remove this worm, delete all files that are detected as VBS.Netlog.I and undo the changes that it made to the registry. Here are the steps:

To remove the worm:
  1. Run LiveUpdate to make sure that you have the most recent virus definitions.
  2. Start Norton AntiVirus (NAV), and run a full system scan. Be sure that NAV is configured to scan all files.
  3. Delete all files that are detected as VBS.Netlog.I.

To edit the registry:

CAUTION : We strongly recommend that you back up the system registry before you make any changes. Incorrect changes to the registry could result in permanent data loss or corrupted files. Please make sure that you modify only the keys that are specified. Please see the document How to back up the Windows registry before you proceed.

NOTE: Not all keys or values will exist on all computers.
  1. Click Start, and click Run. The Run dialog box appears.
  2. Type regedit and then click OK. The Registry Editor opens.
  3. Navigate to the key

    HKEY_CURRENT_USER\Software\Microsoft\
    Office\9.0\Word\Security
  4. In the right pane, double-click the value

    Level
  5. In the Value data box, enter either 2 or 3 and then click OK.
  6. Navigate to the key

    HKEY_LOCAL_MACHINE\Software\Microsoft\
    Windows\CurrentVersion\Network
  7. In the right pane, double-click the value

    Installed
  8. In the Value data box, delete the current number and then click OK.
  9. Navigate to the key

    HKEY_LOCAL_MACHINE\Software\Microsoft\
    Windows\CurrentVersion\Network\LanMan
  10. In the left pane, select and then delete the subkey

    Rainbow
  11. Navigate to the key

    HKEY_LOCAL_MACHINE\System\CurrentControlSet\
    Services\VxD\VNETSUP
  12. In the right pane, double-click the value

    ComputerName

    Restore the key to the name that you use for this computer.
  13. Navigate to the key

    HKEY_LOCAL_MACHINE\System\CurrentControlSet\
    Services\VxD\VNETSUP
  14. In the right pane, double-click the value

    FileSharing

    Restore this to either Yes for sharing or No to disable sharing.
  15. Navigate to the key

    HKEY_CLASSES_ROOT\VBSFile
  16. In the right pane, double-click the value

    NeverShowExt

    Restore this to a value of 0.
  17. Exit the Registry Editor.


Writeup By: Douglas Knowles