W32/Smibag.worm

This page shows details and results of our analysis on the malware W32/Smibag.worm

Download Current DAT: 6615

Threat Detail

Malware Type: Virus

Malware Sub-type: Internet Worm

Discovery Date: 2003-09-26

Next Steps:

Overview
Characteristics
Symptoms
Method of Infection
Removal

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

4296 (2003-10-01)

Updated DAT

4298 (2003-10-15)

Minimum Engine

5.1.00

File Length

163,840 bytes (dropper)

Description Added

2003-09-26

Description Modified

2003-09-26

Malware Proliferation

Characteristics

This threat is considered to be a Low-Profiled risk due to the JoonAng Daily article Computers here hit by new worm .

This worm spreads via Microsoft's MSN Messenger program. If MSN Messenger is not installed on the local system, the worm will fail to replicate.

The worm written in Visual C++ sends itself as file smb.exe to online users on MSN messenger. A dos windows is displayed upon executing extracting the following files:

admagic.exe (90.112 bytes) - worm body
atl.dll (69,632 bytes) - Microsoft Visual C++ Active Template Library
raw32x.dll (121 bytes) - data file
sm.dll (57,344 bytes) - dll used by worm
uz.exe (50,688 bytes) - compression utility
test.txt (0 bytes)

There are various porn website links found in the worm body. It is suspected that these links will appear as popup ads, although this was not observed during testing. The links are:

http://sexwal.porno10000hwa.com
http://www.asiasex.jp
http://realbozi.com
http://www.sex-korea.cn
http://hiddensex.jp
http://hyeyoungnude.com
http://www.say0303.com
http://erosasia.com

Symptoms

Presence of the abovementioned files. The worm hooks the following registry keys to run itself at startup:

HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion
\Run "svchost" = C:\ADMAGIC.EXE
HKEY_CLASSES_ROOT\CLSID\{CD03FC97-2C85-4714-A5FF -37821781BE8C}\InprocServer32 "(Default)" = %SYSDIR%\SM.DLL
HKEY_CLASSES_ROOT\TypeLib\{422FB26A-0DB0-4D4C-A65F-91034971476B}\1.0\0\win32 "(Default)" = %SYSDIR%\SM.DLL

Method of Infection

This worm requires MSN Messenger to be running in order to spread. It arrives through MSN Messenger as file smb.exe. If that attachment is accepted and run, the local system is then used to propagate the virus to others

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.