Windows Security Tutorials - Herong's Tutorial Examples - v3.01, 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
About This Windows Security Book
Windows 8: System Security Review
Windows 8: System Security Protection
Windows 8 Defender for Real-Time Protection
Windows 7: System Security Review
Windows 7: System Security Protection
Windows 7 Forefront Client Security
Norton Power Eraser - Anti-Virus Scan Tool
McAfee Virus and Malware Protection Tools
Spybot - Spyware Blocker, Detection and Removal
Keeping IE (Internet Explorer) Secure
Malware (Adware, Spyware, Trojan, Worm, and Virus)
HijackThis - Browser Hijacker Diagnosis Tool
IE Add-on Program Listing and Removal
"Conduit Search" - Malware Detection and Removal
"Tube Dimmer", "Scorpion Saver" or "Adpeak" Malware
Malware Manual Removal Experience
►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
PWS (Password Stealer) Trojan Infection Removal