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Discovered: February 24, 2003
Updated: February 13, 2007 11:43:33 AM
Also Known As: WORM_GIBE.B [Trend], W32/Gibe.b@mm [McAfee], W32/Gibe-D [Sophos], I-Worm.Gibe.b [KAV], Win32.Gibe.B [CA]
Type: Worm
Systems Affected: Windows
CVE References: CVE-2001-0154

W32.Gibe.B@mm is a variant of W32.Gibe@mm . This mass-mailing worm uses Microsoft Outlook and its own SMTP engine to send itself to all the contacts in the Microsoft Outlook Address Book and the Windows Address Book. The email is disguised as a Microsoft Security Update and it arrives with an attachment that has a .exe or .zip file extension.

W32.Gibe.B@mm copies itself as WebLoader.exe to the startup folder of all the mapped remote drives. This worm also attempts to spread through the KaZaA file-sharing network and Internet Relay Chat (IRC). W32.Gibe.B@mm may send itself to some news groups whose URLs are carried by the worm.

This threat is written in the Microsoft Visual Basic programming language.

NOTE: Virus definitions dated on February 25, 2003 may detect this threat as W32.Gibe@mm.

Antivirus Protection Dates

  • Initial Rapid Release version February 25, 2003
  • Latest Rapid Release version September 28, 2010 revision 054
  • Initial Daily Certified version February 25, 2003
  • Latest Daily Certified version September 28, 2010 revision 036
  • Initial Weekly Certified release date February 26, 2003

Click here for a more detailed description of Rapid Release and Daily Certified virus definitions.

Technical Description

When W32.Gibe.B@mm is executed, it does the following:

  1. Displays a fake message the first time that it is run. This message, which is not from Microsoft, is:

    This product is protected by copyright laws and international
    copyright treaties, as well as other intellectual property laws and


    Microsoft and/or its respective suppliers hereby disclaim all warranties
    and conditions with regard to this information, including all warranties
    and conditions of merchantability, whether express, implied or
    statutory, fitness for a particular purpose, title and non-infringement.
    Microsoft does not warrant that the functions for the software or code
    will meet your requirements, or that the operation of the software or
    code will be uninterrupted or error-free, or that defects in the software
    or code can be corrected.  Furthermore, Microsoft does not warrant
    or make any representations regarding the use or the results of the
    use of the software, code or related documentation in terms of their
    correctness, accuracy, reliability, or otherwise. No oral or written
    information or advice given by Microsoft or its authorized
    representatives shall create a warranty or in any way increase the
    scope of this warranty.  Should the software or code prove defective
    after Microsoft has delivered the same, you, and you alone,
    shall assume the entire cost associated with all necessary servicing,
    repair or correction. In no event shall Microsoft and/or its respective
    suppliers be liable for any special, indirect or consequential damages
    or any damages whatsoever resulting from loss of use, data or profits,
    whether in an action of contract, negligence or other tortious action,
    arising out of or in connection with the use or performance of
    software, documents, provision of or failure to provide services, or
    information available from the services.

    2003 Microsoft Corporation, One Microsoft Way,
    Redmond, Washington U.S.A. All rights reserved.
  2. Copies itself as %Windir%\Gibe.dll.

    NOTE: %Windir% is a variable. The worm locates the Windows installation folder (by default, this is C:\Windows or C:\Winnt) and copies itself to that location.
  3. Copies itself to %Windir% and %Temp% as one of the following:
    • Update.exe
    • Update*.exe
    • Patch.exe
    • Patch*.exe
    • P<six random numbers>.exe
    • Q<six random numbers>.exe

      • %Temp% is a variable that represents the Windows temporary folder. For example, this can be C:\Windows\Temp.
      • * represents some random numbers. For example, the worm may copy itself as Update932.exe.

  4. Copies the following files to the %Windir%\ folder:
    • DX3DRndr.exe. This file is a worm component that spreads using Microsoft Outlook and SMTP. It is 73,728 bytes in length.
    • MSBugAdv.exe. This file is the component that searches for the email addresses and writes them to the file, MailViews.db. It is 24,576 bytes in length.
    • MailViews.db. This file contains the email addresses that the worm finds on your computer.
    • WMSysDx.bin. This file contains the URLs to which the worm connects.

  5. Adds the value:

    DxLoad %Windir%\DX3DRndr.exe

    to the registry key:


    so that the worm runs when you start Windows.
  6. Uses WinZip or WinRar to zip itself to a self-extracting file using the original worm file name, with the extension .zip. For example, the zipped copy of the worm can be Update.zip.
  7. Creates the subkey:

    Messenger Setup

    in the registry key:

    Internet Settings

    and adds the following values to this subkey:

    Coded ...by Begbie
    Server Not found
    Email Address Not found
    Disp Name <a string chosen by the worm>
    LookName <name of the copy of the worm>

    The strings used in Disp Name are constructed from the following:


    For example, it can be Internet Mail Automat.

How the worm spreads using email
The worm searches for the location of the Windows Address Book file in the registry key:

HKEY_CURRENT_USER\Software\Microsoft\Wab\WAB4\Wab File Name

It also retrieves the IP address of the SMTP server, name and email address of the current user, and the IP address of the NNTP server. Then, the worm uses Microsoft Outlook and its own SMTP engine to spread to all the contacts in the Outlook Address Book and the Windows Address Book.

Subject: The subject is in the form of:

<%String1%><%String2%><%String3%><%String4%><%String5%><%String6%><%String7%><"from"><%String8%><%String8%>, where:

<%String1%> is one of the following:
  • FW:
  • FWD:
  • RE:
  • <Blank>

<%String2%> is one of the following:
  • Check
  • Check out
  • Prove
  • Taste
  • Try
  • Look at
  • Take a look at
  • See
  • Watch

<%String3%> is one of the following:
  •  these
  •  this
  •  the
  •  that
  • <blank>

< %String4%> is one of the following:
  • correction
  • security
  • <blank>

<%String5%> is one of the following:
  •  update
  •  patch
  •  pack

<%String6%> is one of the following:
  • which
  • <blank>

<%String7%> is one of the following:
  • came
  •  comes

<%String8%> is one of the following:
  • the
  • <blank>

<%String9%> is one of the following:
  • M$ Corporation
  • Microsoft

For example, the subject line can be:

FWD: Watch this security update which comes from Microsoft.

Attachment: The attached file can be a copy of the worm, or its zipped/"rarred" copy. The file name can be one of the following, with .exe or .zip as an extension:
  • update
  • update<random numbers>
  • patch
  • patch<random numbers>
  • p<six random numbers>
  • q<six random numbers>

Message: The email may not have a message, or the message can be:

----- Original message follows -----
Microsoft <%string%>

this is the latest version of security update, the
<current month and year, for example, Feburuary 2003>, Cumulative Patch update which eliminates all
known security vulnerabilities affecting Internet Explorer,
Outlook and Outlook Express as well as five newly discovered
vulnerabilities. Install now to protect your computer from these
vulnerabilities, the most serious of which could allow an attacker to
run executable on your system. This update includes the functionality
of all previously released patches.

System requirements:
Win 9x/Me/2000/NT/XP

This update applies to:
Microsoft Internet Explorer, version 4.01 and later
Microsoft Outlook, version 8.00 and later
Microsoft Outlook Express, version 4.01 and later

Customers should install the patch at the earliest opportunity.

How to install:
Run attached file. Click Yes on displayed dialog box.

How to use:
You don't need to do anything after installing this item.

Microsoft Technical Support is available at

For security-related information about Microsoft products,
please visit the Microsoft Security Advisor web site at

Contact us at

Please do not reply to this message. It was sent from an unmonitored
e-mail address and we are unable to respond to any replies.

Thank you for using Microsoft products.

%string% is one of the following:
  • Client
  • Consumer
  • Partner
  • User

How the worm spreads through KaZaA
The worm may create a subfolder under the %Temp% folder. The subfolder's name is randomly generated.

The worm retrieves the location of the KaZaA download folder from the DownloadDir value in the registry key:


and adds the following values to this registry key:

Dir99 %Temp%\<the subfolder created by the worm>
DisableSharing 0

Then, the worm copies itself to the KaZaA download folder and the aforementioned subfolder as one of the following:
  • IEPatch.exe
  • KaZaA upload.exe
  • Porn.exe
  • XboX Emulator.exe
  • PS2 Emulator.exe
  • XP update.exe
  • XXX Video.exe
  • Sick Joke.exe
  • Free XXX Pictures.exe
  • My naked sister.exe
  • Hallucinogenic Screensaver.exe
  • Cooking with Cannabis.exe
  • Magic Mushrooms Growing.exe
  • I-Worm_Gibe Cleaner.exe

How the worm spreads through mapped drives
The worm is network-aware. It attempts to locate the Startup folder on all the mapped network drives as follows:
  • Windows 2000: On Windows 2000 computers, the worm attempts to copy itself to:

    \Documents and Settings\%Infected Computer User Name%\Start Menu\Programs\Startup.

    NOTE: %Infected Computer User Name% is a variable. For example, if the logged-in user of the infected computer is "Administrator," the worm would copy itself to:

    \Documents and Settings\Administrator\Start Menu\Programs\Startup

    on the remote computer.
  • Windows 98: On Windows 98 computers, the worm attempts to copy itself to:

    \Windows\Start Menu\Programs\Startup

    on the remote computer.
  • Windows NT: On Windows NT Computers, the worm attempts to copy itself to:

    \Winnt\Profiles\%Infected Computer User Name%\Start Menu\Programs\Startup

    NOTE: %Infected Computer User Name% is a variable. For example, if the logged-in user of the infected computer is "Administrator," the worm would copy itself to:

    \Winnt\Profiles\Administrator\Start Menu\Programs\Startup

    on the remote computer.

Then, the worm copies itself as WebLoader.exe to the startup folder of all the mapped remote drives.

How the worm spreads through mIRC
W32.Gibe.B@mm searches for the \Mirc folder. It creates the Script.ini file in this folder. The worm uses this script file to send itself to other mIRC users who connect on the same channel as the infected computer.


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.


The following instructions pertain to all current and recent Symantec antivirus products, including the Symantec AntiVirus and Norton AntiVirus product lines.

  1. Update the virus definitions.
  2. Run a full system scan and delete all the files detected as W32.Gibe.B@mm.
  3. Delete the value that was added to the registry.

For specific details on each of these steps, read the following instructions.

1. Updating the virus definitions
Symantec Security Response fully tests all the virus definitions for quality assurance before they are posted to our servers. There are two ways to obtain the most recent virus definitions:
  • Running LiveUpdate, which is the easiest way to obtain the virus definitions: These virus definitions are posted to the LiveUpdate servers once each week (usually on Wednesdays), unless there is a major virus outbreak. To determine whether definitions for this threat are available by LiveUpdate, refer to the Virus Definitions (LiveUpdate), in the "Protection" section, at the top of this writeup.
  • Downloading the definitions using the Intelligent Updater: The Intelligent Updater virus definitions are posted on U.S. business days (Monday through Friday). You should download the definitions from the Symantec Security Response Web site and manually install them. To determine whether definitions for this threat are available by the Intelligent Updater, refer to the Virus Definitions (Intelligent Updater), in the "Protection" section, at the top of this writeup.

    The Intelligent Updater virus definitions are available here. For detailed instructions on how to download and install the Intelligent Updater virus definitions from the Symantec Security Response Web site, click here.

2. Scanning for and deleting the infected files
  1. Start your Symantec antivirus program and make sure that it is configured to scan all the files.
  2. Run a full system scan.
  3. If any files are detected as infected with W32.Gibe.B@mm, click Delete.

3. Deleting the value from the registry

CAUTION : Symantec strongly recommends that you back up the registry before you make any changes to it. Incorrect changes to the registry can result in permanent data loss or corrupted files. Modify the specified keys only. Read the document, "How to make a backup of the Windows registry ," for instructions.
  1. Click Start, and then click Run. (The Run dialog box appears.)
  2. Type regedit

    Then click OK. (The Registry Editor opens.)
  3. Navigate to the key:

  4. In the right pane, delete the value:

    DxLoad %Windir%\DX3DRndr.exe
  5. Exit the Registry Editor.

Writeup By: Yana Liu