What Is Vundo Related vtsts.dll?

This section provides a tutorial example of how to find the root file of trojan Vundo, vtsts.dll.

Of course, this time I had to do more than removing these DLL files. I had to try to find the root of this Trojan Vundo.

So I looked at the HijackThis report carefully again, examining each entry in the report and did Google search on each associated program. When I reached the following entry, I got some interested matches on Google search result:

O2 - BHO: ATLDistrib Object - {93C6313C-9DB4-4694-8BD0-E378C573A9AD}
   - C:\WINDOWS\system32\vtsts.dll

Google Search Result - Part I: When I searched for "vtsts.dll" with Google, I got the following interesting items out of 785 matches:

1. From www.bullguard.com/forum/8/DowloadTrojan-Virus-vtstsdll_14346.html, it's a long forum post and replies dated on May 7, 2005. The infected system has 2 related entries in its HijackThis report:

O2 - BHO: (no name) - {8E13DDE1-E013-47ec-9C4C-27C2F78BDD26}
   - C:\WINDOWS\system32\vtsts.dll
O20 - Winlogon Notify: vtsts - C:\WINDOWS\SYSTEM32\vtsts.dll

Based on the replies, the infected system was cleaned by AVG Antivirus from www.grisoft.com, after several failed attempts from different anti-virus tools.

2. From forums.techguy.org/security/415370-solved-help-remove-downloader-trojan.html, it's a long forum post and replies date on Nov. 9, 2005. The infected system has 3 related entries in its HijackThis report:

O2 - BHO: (no name) - {00DBDAC8-4691-4797-8E6A-7C6AB89BC441}
   - C:\WINDOWS\system32\vtsts.dll
O20 - Winlogon Notify: vtsqr - C:\WINDOWS\system32\vtsqr.dll
O20 - Winlogon Notify: vtsts - C:\WINDOWS\SYSTEM32\vtsts.dll

Based on the replies, the infected system was cleaned by using VundoFix.exe from atribune.org and Killbox from subratam.org, combined with detailed guiding instructions providing by the forum moderator, Flrman1.

This tells me that vtsts.dll is related to Trojan Vundo.

3. From www.lavasoftsupport.com/lofiversion/index.php/t1570.html, it's a long forum post and replies date on Jul. 5, 2006. The infected system has 4 related entries in its HijackThis report:

O2 - BHO: (no name) - {20D57A66-F7DF-467d-907B-9B7F4A118AB7} 
   - C:\WINDOWS\system32\mllmm.dll
O2 - BHO: DosSpecFolder Object {3496D13A-609A-407B-B181-8F47B4F28AE9}
   - C:\WINDOWS\system32\vtsts.dll
O20 - Winlogon Notify: mllmm - C:\WINDOWS\SYSTEM32\mllmm.dll
O20 - Winlogon Notify: vtsts - C:\WINDOWS\system32\vtsts.dll

Removal instuctions were given to use Qoofix from malwarebytes.org and VundoFix.exe from atribune.org. But no final reply on the results of the suggested removal process on the infected system.

Google Search Result - Part II: When I searched for "ATLDistrib Object" with Google, I got the following interesting items out of 9,940 matches:

1. From wiki.castlecops.com/Malware_Removal:_Virtumundo, it's an article about Adware-Virtumundo (Vundo) removal. There are two sets of HijackThis report entries related ATLDistrib Object:

Example 1:
O2 - BHO: ATLDistrib Object - {7A1A109F-58B3-414B-9829-5F4D9BE5FEDE}
   - C:\WINDOWS\system32\mljjj.dll
O20 - Winlogon Notify: mljjj - C:\WINDOWS\system32\mljjj.dll

Example 2:
O2 - BHO: ATLDistrib Object - {7A1A109F-58B3-414B-9829-5F4D9BE5FEDE}
   - C:\WINDOWS\system32\pmnlj.dll
020 - Winlogon Notify: pmnlj - C:\WINDOWS\system32\pmnlj.dll

This confirms that vtsts.dll is related to Trojan Vundo.

2. From www.geekstogo.com/forum/index.php?showtopic=86351, it's a forum post and replies dated on Dec. 23, 2005. The infected system has 2 related entries in its HijackThis report:

O2 - BHO: ATLDistrib Object - {3FE36807-69ED-45D1-B9BE-85C0E3F75B6A}
   - C:\WINDOWS\System32\ddccd.dll
O20 - Winlogon Notify: ddccd - C:\WINDOWS\System32\ddccd.dll

Based on the replies, the infected system was cleaned by using VundoFix.exe, WebRoot SpySweeper, VirtumundoBegone, Panda Active Scan, and Killbox, combined with detailed guiding instructions providing by the Malware Removal Specialist, loophole.

This confirms again that vtsts.dll is related to Trojan Vundo.

Conclusion: vtsts.dll and "ATLDistrib Object" are related to Trojan Vundo. I must missed the vtsts.dll entry from the HijackThis report during my last visit.

From my Google results, all reported cases are having the suspicious DLL file registered as a Winlogon Notify entry. But I could not find any similar "020" entry in my friend's HijackThis report. So this could be new variant of Trojan Vundo.

Or this is a partial broken Trojan Vundo. This seemed to match the symptom that the Internet Explorer pops up, but not showing any target Web sites, and closes up by itself.

Table of Contents

 About This Book

 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

 What Is Trojan Vundo?

 Partial Removal of Trojan Vundo

 Detecting Trojan Vundo with McAfee VirusScan

 McAfee VirusScan and

 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

 Startup Programs Removal for Better System Performance

 Winsock - Windows Sockets API

 Java on Windows

 Glossary of Terms

 Outdated Tutorials

 References

 PDF Printing Version