W32/Gibe.A@mm

Analysis

• Virus is 32bit, with a size of 122,880 bytes and pretends to be an update from Microsoft
  
• Virus is written in Visual Basic 6 and requires MSVBVM60.DLL on a host system in order to be a threat
  
• Virus contains additional files, which are LZ compressed, and extracts them to the host during execution
  
• When first run, virus may display a message box -
  Title Bar: Microsoft Internet Tools Update
  Body Text: This will install Microsoft Security Update.
  
• Choosing either yes or now will install the virus to the local system; the virus creates several files onto the local system -

  C:\WINDOWS\Q216309.EXE [copy of virus]
  C:\WINDOWS\SYSTEM\VTNMSCCD.DLL [copy of virus]
  C:\WINDOWS\BCTOOL.EXE [emailing component of virus]
  C:\WINDOWS\WINNETW.EXE [email address gathering component]
  C:\WINDOWS\GFXACC.EXE [remote access Trojan]
  C:\WINDOWS\02_N803.DAT [list of email addresses collected]
  

• Virus modifies the registry to load at Windows startup -

  HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\
  CurrentVersion\Run\

  LoadDBackUp=C:\WINDOWS\BcTool.exe
  3Dfx Acc=C:\WINDOWS\GFXAcc.exe

• Virus also makes another entry in the registry to alert the virus it has infected the host system -

  HKEY_LOCAL_MACHINE\Software\AVTech\Settings\
  Installed=... by Begbie

• Virus creates an email message and sends it out in this format -

  From: "Microsoft Corporation Security Center" <rdquest12@microsoft.com>
  Reply-To: <rdquest12@microsoft.com>
  To: "Microsoft Customer" <'customer@yourdomain.com'>
  Subject: Internet Security Update
  Body:
  Microsoft Customer,

  this is the latest version of security update, the update which eliminates all 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.
  ----------------------------------------
  ----------------------------------------
  Microsoft is registered trademark of Microsoft Corporation.
  Windows and Outlook are trademarks of Microsoft Corporation.

  Attachment: "q216309.exe"

  * It's important to note that Microsoft does not send binary files by email.