Windows Tutorials - Herong's Tutorial Examples - v5.62, by Dr. Herong Yang
Removing xxxxxxxx.dll Files Generated by Vundo
This section provides a tutorial example of how to remove DLL files generated by trojan Vundo.
Of course, my friend called me a couple of weeks after I helped him on analyzing his adware infected Windows system. If you read previous sections of this chapter, you know that I was only able to identify that the infection was a Trojan Vundo. I was able to remove only some DLL files named with 8 random letters. His infection was not fully removed.
So I visited his Windows system again. After spending a couple of hours, I believe I did a full removal of a Trojan Vundo from his Windows system. Here are my notes that may help you if your Windows system gets a similar infection.
Symptom: My friend told me that the same behavior was still happening. Once a while, Internet Explorer will start a new window. That new window will run something for a few seconds causing CPU usage to go near 100%, then close itself.
HijackThis Findings: Running HijackThis and comparing the report with the report from my last visit, I saw new "O2 - BHO" line like this:
O2 - BHO: (no name) - {F18F04B0-9CF1-4b93-B004-77A288BEE28B}
- C:\WINDOWS\system32\gidijvia.dll
File System Checking: Using File Explorer, I saw two suspicious DLL files:
>dir C:\WINDOWS\system32\*.dll 10/29/2006 09:34 PM 60,436 swcskmxu.dll 10/31/2006 09:59 PM 60,436 gidijvia.dll
IE Addon Checking: Looking at IE > Internet Options > Programs > Manage Addon, I found the gidijvia.dll entry.
Analysis: Trojan Vundo is hiding somewhere on the system. It keeps creating new DLL files. But these DLL files are having different file sizes, comparing to those I captured from my last visit:
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
My guess is that this Trajon Vundo is periodically going back to its base Website to get updates and produce different versions of DLL files.
Action: I repeated my partial removal process to remove these DLL files:
1. Zipped all 2 suspicious files into a zip file, bho_200611.zip, and tried to delete them:
>del C:\WINDOWS\system32\swcskmxu.dll (deleted) >del C:\WINDOWS\system32\gidijvia.dll (not deleted because it is in use)
2. Closed all Internet Explorer windows and File Explorer windows, and ran HijackThis:
Find and check the gidijvia.dll in the log Click the "Fix checked" button
3. Ran HijackThis again:
Go to Config >> Misc Tools >> Delete a file on reboot Select file: C:\WINDOWS\system32\gidijvia.dll Click Yes to reboot the system
4. Verified the following places:
HijackThis report: clean C:\WINDOWS\system32 directory: clean Internet Explorer add-on list: clean
Table of Contents
Introduction to Microsoft Windows
Introduction to Windows Explorer
Introduction to Internet Explorer
"Paint" Program and Computer Graphics
GIMP - GNU Image Manipulation Program
JPEG Image File Format Quality and Size
GIF Image File Format and Transparent Background
"WinZip" - ZIP File Compression Tool
"WinRAR" - RAR and ZIP File Compression Tool
FTP Server, Client and Commands
"FileZilla" - Free FTP Client and Server
Web Server Log Files and Analysis Tool - "Analog"
Spyware Adware Detection and Removal
IE Addon Program Listing and Removal
►Vundo (VirtuMonde/VirtuMundo) - vtsts.dll Removal
Partial Removal of Trojan Vundo
Detecting Trojan Vundo with McAfee VirusScan
Instructions on Full Removal of Trojan Vundo
►Removing xxxxxxxx.dll Files Generated by Vundo
What Is Vundo Related vtsts.dll
Finding and Removing vtsts.dll Manually
Removing Trojan Vundo with FixVundo.exe from Symantec
Removing Trojan Vundo with VundoFix.exe from Atribune.org
Trojan and Malware "Puper" Description and Removal
VSToolbar (VSAdd-in.dll) - Description and Removal
Spybot - Spyware Blocker, Detection and Removal
Setting Up and Using Crossover Cable Network
Home Network Gateway - DSL Modem/Wireless Router
Windows Task Manager - The System Performance Tool
"tasklist" Command Line Tool to List Process Information
"msconfig" - System Configuration Tool
Configuring and Managing System Services
Windows Registry Key and Value Management Tools