Windows Tutorials - Herong's Tutorial Notes
Dr. Herong Yang, Version 4.20

Trojan and Adware - Vundo (VirtuMonde/VirtuMundo)

Part:   1  2  3  4 

Windows Tutorials - Herong's Notes © 2006 Dr. Herong Yang

Adware - VSAdd-in.dll and Removal

Trojan and Adware - Vundo

Controlling IE Addons

Removing Spyware

Web Log Analysis

Paint - Graphics Tool

WinRAR - RAR Compression Tool

FTP Server and Client

Crossover Cable Network

... Table of Contents

(Continued from previous part...)

Experience of Removing Trojan Vundo

Based on what my friend told me, once a while, Internet Explorer will starts a new window. That new window will run something for a few seconds causing CPU usage to go near 100%, then close itself.

When I ran HijackThis, it reported this line:

O2 - BHO: (no name) - {1DAEFCB9-06C8-47c6-8F20-3FB54B244DAA} 
   - C:\WINDOWS\system32\yjsallam.dll

Starting from HijackThis report, I did the following to try to remove this Internet add-on program.

1. Looked at C:\WINDOWS\system32, and found the following suspicious files:

>dir C:\WINDOWS\system32
10/02/2006  10:42 PM            86,068 fcissfvg.dll
10/03/2006  10:31 PM            86,036 lyssmlnb.dll
10/12/2006  09:52 PM            98,324 yjsallam.dll

2. Looked at IE > Internet Options > Programs > Manage Addon, found the yjsallam.dll entry, and disabled it.

3. Zipped all 3 suspicious files into a zip file, bho_200610.zip, and tried to delete them:

>del C:\WINDOWS\system32\fcissfvg.dll
   (deleted)

>del C:\WINDOWS\system32\lyssmlnb.dll
   (deleted)

>del C:\WINDOWS\system32\yjsallam.dll
   (not deleted because it is in use)

4. Closed all Internet Explorer windows and File Explorer windows, and ran HiJackThis:

Find and check the yjsallam.dll in the log
Click the "Fix checked" button

5. Ran HijackThis again:

Go to Config >> Misc Tools >> Delete a file on reboot
Select file: C:\WINDOWS\system32\yjsallam.dll
Click Yes to reboot the system

6. Verified the following places:

HijackThis report: clean
C:\WINDOWS\system32 directory: clean
Internet Explorer add-on list: clean

The result seemed to be ok. But I knew that this was just a partial removal. The virus was still on my friend's computer. It is hidden somewhere and will create another trojan DLL file named with 8 random letters some time later on. Since I don't have any software tool to find and remove the root of the virus, I told my friend to check C:\WINDOWS\system32 directory regularly. If there are any new DLL files, dated after today, with 8-letter names, just call me for help.

(Continued on next part...)

Part:   1  2  3  4 

Dr. Herong Yang, updated in 2006
Windows Tutorials - Herong's Tutorial Notes - Trojan and Adware - Vundo (VirtuMonde/VirtuMundo)