TROJ_DLOADR.WTT

March 11, 2011
 Analysis by: Sabrina Sioting
 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 DISTRIBUTION POTENTIAL:
 REPORTED INFECTION:

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

This Trojan acts as a Browser Helper Object (BHO) that monitors a user's Internet-browsing habits.

  TECHNICAL DETAILS

File Size:

1,901,890 bytes

File Type:

PE

Memory Resident:

No

Initial Samples Received Date:

02 Mar 2011

Installation

This Trojan drops the following files:

  • %User Profile%\Application Data\Toolbar4\{338B4DFE-2E2C-4338-9E41-E176D497299E}\affid.dat
  • %User Profile%\Application Data\Toolbar4\{338B4DFE-2E2C-4338-9E41-E176D497299E}\basis.xml
  • %User Profile%\Application Data\Toolbar4\{338B4DFE-2E2C-4338-9E41-E176D497299E}\cache
  • %User Profile%\Application Data\Toolbar4\{338B4DFE-2E2C-4338-9E41-E176D497299E}\icons.bmp
  • %User Profile%\Application Data\Toolbar4\{338B4DFE-2E2C-4338-9E41-E176D497299E}\include_files
  • %User Profile%\Application Data\Toolbar4\{338B4DFE-2E2C-4338-9E41-E176D497299E}\info.txt
  • %User Profile%\Application Data\Toolbar4\{338B4DFE-2E2C-4338-9E41-E176D497299E}\install.ico
  • %User Profile%\Application Data\Toolbar4\{338B4DFE-2E2C-4338-9E41-E176D497299E}\mbback.bmp
  • %User Profile%\Application Data\Toolbar4\{338B4DFE-2E2C-4338-9E41-E176D497299E}\mbbigopen.bmp
  • %User Profile%\Application Data\Toolbar4\{338B4DFE-2E2C-4338-9E41-E176D497299E}\mbclose.bmp
  • %User Profile%\Application Data\Toolbar4\{338B4DFE-2E2C-4338-9E41-E176D497299E}\mbfwd.bmp
  • %User Profile%\Application Data\Toolbar4\{338B4DFE-2E2C-4338-9E41-E176D497299E}\mbsep.bmp
  • %User Profile%\Application Data\Toolbar4\{338B4DFE-2E2C-4338-9E41-E176D497299E}\nav1c.bmp
  • %User Profile%\Application Data\Toolbar4\{338B4DFE-2E2C-4338-9E41-E176D497299E}\tbcore3.inf
  • %User Profile%\Application Data\Toolbar4\{338B4DFE-2E2C-4338-9E41-E176D497299E}\TbHelper2.exe
  • %User Profile%\Application Data\Toolbar4\{338B4DFE-2E2C-4338-9E41-E176D497299E}\uninstall.exe
  • %User Profile%\Application Data\Toolbar4\{338B4DFE-2E2C-4338-9E41-E176D497299E}\UninstallToolbar.exe
  • %User Profile%\Application Data\Toolbar4\{338B4DFE-2E2C-4338-9E41-E176D497299E}\update.exe
  • %User Profile%\Application Data\Toolbar4\{338B4DFE-2E2C-4338-9E41-E176D497299E}\version.txt
  • %User Temp%\Burn4Free DB Toolbar.xpi
  • %User Temp%\ietb.cab
  • %User Temp%\nsk4.tmp\NSISpcre.dll
  • %Program Files%\Burn4Free DB Toolbar\affid.dat
  • %Program Files%\Burn4Free DB Toolbar\alert_plugin.dll
  • %Program Files%\Burn4Free DB Toolbar\basis.xml
  • %Program Files%\Burn4Free DB Toolbar\CustomTabPage.dll
  • %Program Files%\Burn4Free DB Toolbar\icons.bmp
  • %Program Files%\Burn4Free DB Toolbar\info.txt
  • %Program Files%\Burn4Free DB Toolbar\install.ico
  • %Program Files%\Burn4Free DB Toolbar\MacroParserPlugin.dll
  • %Program Files%\Burn4Free DB Toolbar\mbback.bmp
  • %Program Files%\Burn4Free DB Toolbar\mbbigopen.bmp
  • %Program Files%\Burn4Free DB Toolbar\mbclose.bmp
  • %Program Files%\Burn4Free DB Toolbar\mbfwd.bmp
  • %Program Files%\Burn4Free DB Toolbar\mbsep.bmp
  • %Program Files%\Burn4Free DB Toolbar\nav1c.bmp
  • %Program Files%\Burn4Free DB Toolbar\somoto.dll
  • %Program Files%\Burn4Free DB Toolbar\TbCommonUtils.dll
  • %Program Files%\Burn4Free DB Toolbar\tbcore3.dll
  • %Program Files%\Burn4Free DB Toolbar\tbcore3.inf
  • %Program Files%\Burn4Free DB Toolbar\tbhelper.dll
  • %Program Files%\Burn4Free DB Toolbar\TbHelper2.exe
  • %Program Files%\Burn4Free DB Toolbar\uninstall.exe
  • %Program Files%\Burn4Free DB Toolbar\UninstallToolbar.exe
  • %Program Files%\Burn4Free DB Toolbar\update.exe
  • %Program Files%\Burn4Free DB Toolbar\version.txt

(Note: %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.. %Program Files% is the default Program Files folder, usually C:\Program Files.)

It creates the following folders:

  • %User Profile%\Application Data\Toolbar4
  • %User Profile%\Application Data\Toolbar4\{338B4DFE-2E2C-4338-9E41-E176D497299E}
  • %Program Files%\Burn4Free DB Toolbar

(Note: %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.. %Program Files% is the default Program Files folder, usually C:\Program Files.)

Autostart Technique

This Trojan acts as a Browser Helper Object (BHO) that monitors a user's Internet-browsing habits.

Other System Modifications

This Trojan adds the following registry entries as part of its installation routine:

HKEY_CLASSES_ROOT\Software\Microsoft\
Internet Explorer\Main
Start Page = http://www.{BLOCKED}kpro.com/burn4free/{693E98B4-E992-4D10-9452-82837E33E007}

HKEY_CLASSES_ROOT\CLSID\{338B4DFE-2E2C-4338-9E41-E176D497299E}
@ = Burn4Free DB Toolbar

HKEY_CLASSES_ROOT\SMTTB2009.SMTTB2009.3
@ = Burn4Free DB Toolbar

HKEY_CLASSES_ROOT\SMTTB2009.SMTTB2009
@ = Burn4Free DB Toolbar

Download Routine

This Trojan connects to the following URL(s) to download its component file(s):

  • http://www.{BLOCKED}edpro.com

  SOLUTION

Minimum Scan Engine:

8.900

FIRST VSAPI PATTERN FILE:

7.868.05

FIRST VSAPI PATTERN DATE:

02 Mar 2011

Step 1

For Windows ME and XP users, before doing any scans, please make sure you disable System Restore to allow full scanning of your computer.

Step 2

Search and delete this folder

[ Learn More ]
Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden folders in the search result.
  • %User Profile%\Application Data\Toolbar4
  • %Program Files%\Burn4Free DB Toolbar

Step 3

Search and delete this file

[ Learn More ]
There may be some component files that are hidden. Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden files and folders in the search result.
%User Temp%\Burn4Free DB Toolbar.xpi
%User Temp%\ietb.cab
%User Temp%\nsk4.tmp\NSISpcre.dll

Step 4

Delete this registry value

[ Learn More ]

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_CLASSES_ROOT\SMTTB2009.SMTTB2009
    • @ = Burn4Free DB Toolbar
  • In HKEY_CLASSES_ROOT\SMTTB2009.SMTTB2009.3
    • @ = Burn4Free DB Toolbar
  • In HKEY_CLASSES_ROOT\CLSID\{338B4DFE-2E2C-4338-9E41-E176D497299E}
    • @ = Burn4Free DB Toolbar
  • In HKEY_CLASSES_ROOT\Software\Microsoft\Internet Explorer\Main
    • Start Page = http://www.{BLOCKED}pro.com/burn4free/{693E98B4-E992-4D10-9452-82837E33E007}

Step 5

Scan your computer with your Trend Micro product to delete files detected as TROJ_DLOADR.WTT 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.


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