TROJ_VUNDO.DCV
Adware:Win32/AdRotator (Microsoft); [3.nsis]:AdClicker-GO.dll (McAfee); Adware.Begin2search (Symantec); ARC:NSIS, [data0003]:Trojan-Clicker.Win32.Agent.cfp (Kaspersky); Trojan.Win32.Generic!BT (Sunbelt); Trojan.Generic.1942669 (FSecure)
Windows 2000, Windows, XP, Windows Server 2003

Threat Type: Trojan
Destructiveness: No
Encrypted:
In the wild: Yes
OVERVIEW
This Trojan arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.
TECHNICAL DETAILS
152,118 bytes
EXE
Yes
05 Dec 2011
Arrival Details
This Trojan arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.
Installation
This Trojan creates the following folders:
- %System Root%\DOCUME~1
- %System Root%\DOCUME~1\ADMINI~1
- %User Profile%\LOCALS~1
- %User Temp%\nsw3.tmp
(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.. %User Profile% is the current user's profile folder, which is usually C:\Windows\Profiles\{user name} on Windows 98 and ME, C:\WINNT\Profiles\{user name} on Windows NT, and C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003.. %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003.)
Autostart Technique
This Trojan adds the following registry entries to enable its automatic execution at every system startup:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
{d32c08d2-ba08-34cb-419d-8ebf69048599} = {random characters}
Other System Modifications
This Trojan deletes the following files:
- %User Temp%\nsg1.tmp
- %User Temp%\nsw3.tmp
(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003.)
It deletes the following folders:
- %User Temp%\nsw3.tmp\
(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003.)
It adds the following registry keys:
HKEY_CURRENT_USER\SOFTWARE\{5A45DC5A-92D6-3410-2CB5-E8E91799AD18}
HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows\CurrentVersion\Uninstall\
gooochi
It adds the following registry entries:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings\
Zones\3
2500 = 3
HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Main
NoProtectedModeBanner = 1
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
gooochi
DisplayName = "Enhancement Browser Tools Gooochi"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
gooochi
UninstallString = "%System%\ufsieksnprm.exe"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
gooochi
DisplayVersion = "2.0.1.4"
HKEY_CURRENT_USER\Software\{5A45DC5A-92D6-3410-2CB5-E8E91799AD18}
day = 5
It modifies the following registry entries:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
DirectDraw\MostRecentApplication
Name = "iexplore.exe"
(Note: The default value data of the said registry entry is mshta.exe.)
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
DirectDraw\MostRecentApplication
ID = 4117b81
(Note: The default value data of the said registry entry is 41107b3f.)
Dropping Routine
This Trojan drops the following files:
- %User Temp%\nsw2.tmp
- %User Temp%\nsw3.tmp\System.dll
- %System%\crorncmlhbiuia.dll
- %System%\ufsieksnprm.exe
- %User Temp%\nsw3.tmp\NSISdl.dll
- %User Temp%\activation_key
- %User Profile%\Application Data\Microsoft
- %User Profile%\Microsoft\Crypto
- %User Profile%\Crypto\RSA
- %User Profile%\RSA\S-1-5-21-4025279379-4087772427-2915903831-500
(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003.. %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and ME, C:\WINNT\System32 on Windows NT and 2000, or C:\Windows\System32 on Windows XP and Server 2003.. %User Profile% is the current user's profile folder, which is usually C:\Windows\Profiles\{user name} on Windows 98 and ME, C:\WINNT\Profiles\{user name} on Windows NT, and C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003.)
This report is generated via an automated analysis system.
SOLUTION
9.200
Step 1
For Windows XP and Windows Server 2003 users, before doing any scans, please make sure you disable System Restore to allow full scanning of your computer.
Step 2
Restart in Safe Mode
Step 3
Delete this registry key
Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.
- In HKEY_CURRENT_USER\SOFTWARE
- {5A45DC5A-92D6-3410-2CB5-E8E91799AD18}
- In HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Uninstall
- gooochi
Step 4
Delete this registry value
Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
- {d32c08d2-ba08-34cb-419d-8ebf69048599}={random characters}
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\3
- 2500=3
- In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main
- NoProtectedModeBanner=1
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\gooochi
- DisplayName="Enhancement Browser Tools Gooochi"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\gooochi
- UninstallString="%System%\ufsieksnprm.exe"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\gooochi
- DisplayVersion="2.0.1.4"
- In HKEY_CURRENT_USER\Software\{5A45DC5A-92D6-3410-2CB5-E8E91799AD18}
- day=5
Step 5
Restore this modified registry value
Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\DirectDraw\MostRecentApplication
- From: Name="iexplore.exe"
To: Name=mshta.exe
- From: Name="iexplore.exe"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\DirectDraw\MostRecentApplication
- From: ID=4117b81
To: ID=41107b3f
- From: ID=4117b81
Step 6
Search and delete these folders
- %System Root%\DOCUME~1
- %System Root%\DOCUME~1\ADMINI~1
- %User Profile%\LOCALS~1
- %User Temp%\nsw3.tmp
Step 7
Search and delete these files
- %User Temp%\nsw2.tmp
- %User Temp%\nsw3.tmp\System.dll
- %System%\crorncmlhbiuia.dll
- %System%\ufsieksnprm.exe
- %User Temp%\nsw3.tmp\NSISdl.dll
- %User Temp%\activation_key
- %User Profile%\Application Data\Microsoft
- %User Profile%\Microsoft\Crypto
- %User Profile%\Crypto\RSA
- %User Profile%\RSA\S-1-5-21-4025279379-4087772427-2915903831-500
Step 8
Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_VUNDO.DCV. If the detected files have already been cleaned, deleted, or quarantined by your Trend Micro product, no further step is required. You may opt to simply delete the quarantined files. Please check this Knowledge Base page for more information.
Step 9
Restore this file from backup only Microsoft-related files will be restored. If this malware/grayware also deleted files related to programs that are not from Microsoft, please reinstall those programs on you computer again.
- %User Temp%\nsg1.tmp
- %User Temp%\nsw3.tmp
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