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Dubbed W32.Gibe by antivirus vendors, the Gibe worm arrives in email disguised as Microsoft's security update MS02-005. The email message even contains a link to Microsoft's critical updates listing for Internet Explorer in an attempt to legitimize the attachment. In actuality, if the attached file is opened, a dialog box is displayed asking: "This will install Microsoft Security Update. Do you wish to continue?" Regardless of choice, the worm drops a remote access Trojan onto the system, modifies the registry, and mass-mails itself to others. The Gibe worm email has the following characteristics:

From: "Microsoft Corporation Security Center"
To: "Microsoft Customer"
Subject: Internet Security Update

Microsoft Customer,

     this is the latest version of security update, the known security vulnerabilities affecting Internet Explorer and MS Outlook/Express as well as six new vulnerabilities, and is discussed in Microsoft Security Bulletin MS02-005. Install now to protect your computer from these vulnerabilities, the most serious of which could allow an attacker to run code on your computer.

Description of several well-know vulnerabilities:

- "Incorrect MIME Header Can Cause IE to Execute E-mail Attachment" vulnerability. If a malicious user sends an affected HTML e-mail or hosts an affected e-mail on a Web site, and a user opens the e-mail or visits the Web site, Internet Explorer automatically runs the executable on the user's computer.

- A vulnerability that could allow an unauthorized user to learn the location of cached content on your computer. This could enable the unauthorized user to launch compiled HTML Help (.chm) files that contain shortcuts to executables, thereby enabling the unauthorized user to run the executables on your computer.

- A new variant of the "Frame Domain Verification" vulnerability could enable a malicious Web site operator to open two browser windows, one in the Web site's domain and the other on your local file system, and to pass information from your computer to the Web site.

- CLSID extension vulnerability. Attachments which end with a CLSID file extension do not show the actual full extension of the file when saved and viewed with Windows Explorer. This allows dangerous file types to look as though they are simple, harmless files - such as JPG or WAV files - that do not need to be blocked.

System requirements:
Versions of Windows no earlier than Windows 95.

This update applies to:
Versions of Internet Explorer no earlier than 4.01
Versions of MS Outlook no earlier than 8.00
Versions of MS Outlook Express no earlier than 4.01

How to install
Run attached file q216309.exe

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

For more information about these issues, read Microsoft Security Bulletin MS02-005, or visit link below.
http://www.microsoft.com/windows/ie/downloads/critical/default.asp
If you have some questions about this article contact us at rdquest12@microsoft.com

Thank you for using Microsoft products.

With friendly greetings,
MS Internet Security Center.
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Microsoft is registered trademark of Microsoft Corporation.
Windows and Outlook are trademarks of Microsoft Corporation.

Removing the worm
Locate and delete the following Registry key:
HKEY_LOCAL_MACHINE\Software\AVTech

Locate and modify the following Registry key: HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run to remove the references to "3dfx Acc" and "LoadDBackup"

Locate and delete the following files:
BCTOOL.EXE, GFXACC.EXE, Q216309.EXE, VTNMSCCD.DLL, WINNETW.EXE, and 02_N803.DAT. You may find it necessary to reboot after the registry changes in order to delete the files.