W32/Gibe@MM

This page shows details and results of our analysis on the malware W32/Gibe@MM

Overview

This is a virus detection. Viruses are programs that self-replicate recursively, meaning that infected systems spread the virus to other systems, which then propagate the virus further. While many viruses contain a destructive payload, it's quite common for viruses to do nothing more than spread from one system to another.


Minimum DAT

4189 (2002-03-06)

Updated DAT

4317 (2004-01-21)

Minimum Engine

5400.1158

File Length

122,880 bytes

Description Added

2002-03-04

Description Modified

2003-10-17

Malware Proliferation

Characteristics

-- Update March 12, 2002 --
To date, more than 50% of the W32/Gibe samples received are damaged. The file header is corrupt. Therefore, the files do not run or infect. The 4190 DATs include detection of these corrupted files as W32/Gibe.dam.

This mass-mailing worm masquerades as a Microsoft Security Update patch (named Q216309.EXE) in order to dupe users into executing it.

The worm is intended to be able to mail itself using both Microsoft Outlook and the default SMTP server for the victim machine. However, in testing the worm was buggy, and did not successfully use Outlook to spread.

Once executed, the worm retrieves the default Internet Account details from the Registry, and creates the following keys, writing this data there:

  • HKEY_LOCAL_MACHINE\Software\AVTech
  • HKEY_LOCAL_MACHINE\Software\AVTech\Settings "Default Address"
       (default SMTP email address)
  • HKEY_LOCAL_MACHINE\Software\AVTech\Settings "Default Server"
       (default SMTP server)
  • HKEY_LOCAL_MACHINE\Software\AVTech\Settings "Installed"
       = ...by Begbie

The WINNETW.EXE component of the worm queries two Internet-based email address directories. It parses email addresses from the returned data, writing them to 02_N803.DAT (repeatedly).

The following two Registry keys are set in order to run the worm components:

  • HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run_
       "3dfx Acc" = %windir\GFXACC.EXE
  • HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run_
       "LoadDBackup" = %windir\BCTOOL.EXE

Upon restarting the machine, BCTOOL.EXE runs, mailing the worm to all the email addresses listed in 02_N803.DAT, using the default SMTP server.

The final component of this worm, GFXACC.EXE, is a backdoor Trojan, opening port 12378 on the infected machine. This component is detected as BackDoor-ABJ by the indicated DATs.

Symptoms

1. Presence of the following files:

  • %windir%\BCTOOL.EXE (32,768 bytes)
  • %windir%\WINNETW.EXE (20,480 bytes)
  • %windir%\Q216309.EXE (122,880 bytes)
  • %windir%\VTNMSCCD.DLL (122,880 bytes)
  • %windir%\GFXACC.EXE (20,480 bytes)
  • %windir%\02_N803.DAT (variable)

2. Port 12378 open.

3. Existence of the following Registry key:

  • HKEY_LOCAL_MACHINE\Software\AVTech

Method of Infection

This virus spreads via email masquerading as a Microsoft security update file Q216309.EXE. Executing this file infects the local machine:

The following files are dropped:

  • %windir%\BCTOOL.EXE
  • %windir%\WINNETW.EXE
  • %windir%\VTNMSCCD.DLL
  • %windir%\GFXACC.EXE

Modifications to the Registry are made in order to execute the virus components (BCTOOL.EXE and GFXACC.EXE) at system startup.

Removal

All Users:
Use current engine and DAT files for detection and removal.

Modifications made to the system Registry and/or INI files for the purposes of hooking system startup, will be successfully removed if cleaning with the recommended engine and DAT combination (or higher).

But in some particular cases, the following steps need to be taken.

Please go to the Microsoft Recovery Console and restore a clean MBR.

On Windows XP:

  • Insert the Windows XP CD into the CD-ROM drive and restart the computer.
  • When the "Welcome to Setup" screen appears, press R to start the Recovery Console.
  • Select the Windows installation that is compromised and provide the administrator password.
  • Issue 'fixmbr' command to restore the Master Boot Record
  • Follow onscreen instructions.
  • Reset and remove the CD from CD-ROM drive.


On Windows Vista and 7:

  • Insert the Windows CD into the CD-ROM drive and restart the computer.
  • Click on "Repair Your Computer".
  • When the System Recovery Options dialog comes up, choose the Command Prompt.
  • Issue 'bootrec /fixmbr' command to restore the Master Boot Record.
  • Follow onscreen instructions.
  • Reset and remove the CD from CD-ROM drive.

Variants

W32/Gibe.dam