PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • 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

File Size: 230,352 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 08 Jun 2013

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:

  • %Application Data%\newtab

(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Roaming on Windows Vista and 7.)

Autostart Technique

This Trojan adds the following registry entries to enable its automatic execution at every system startup:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
newtab = "%Application Data%\newtab\newtab.exe"

It registers itself as a BHO to ensure its automatic execution every time Internet Explorer is used by adding the following registry keys:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Explorer\
Browser Helper Objects\{36936EFC-0B55-4DF4-A01D-69CD27B4309E}

Other System Modifications

This Trojan adds the following registry keys:

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\TabbedBrowsing

HKEY_CURRENT_USER\Software\_newtab

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Uninstall\
newtab

HKEY_CLASSES_ROOT\CLSID\{36936EFC-0B55-4DF4-A01D-69CD27B4309E}

HKEY_CLASSES_ROOT\CLSID\{36936EFC-0B55-4DF4-A01D-69CD27B4309E}\
InprocServer32

It adds the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\TabbedBrowsing
Enabled = "1"

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\TabbedBrowsing
NewTabPageShow = "0"

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Main
Enable Browser Extensions = "yes"

HKEY_CURRENT_USER\Software\_newtab
User = "68AD0FD0_1922168568153"

HKEY_CURRENT_USER\Software\_newtab
Partner = "newtab"

HKEY_CURRENT_USER\Software\_newtab
sendlog = "20130530"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Uninstall\
newtab
DisplayIcon = "%Application Data%\newtab\newtabdel.exe.exe,0"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Uninstall\
newtab
DisplayName = "newtab"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Uninstall\
newtab
UninstallString = "%Application Data%\newtab\newtabdel.exe"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{36936EFC-0B55-4DF4-A01D-69CD27B4309E}\InprocServer32
ThreadingModel = "Apartment"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Explorer\
Browser Helper Objects\{36936EFC-0B55-4DF4-A01D-69CD27B4309E}
NoExplorer = "1"

It deletes the following registry keys:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Ext\
Settings\{36936EFC-0B55-4DF4-A01D-69CD27B4309E}

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Ext\
Settings\{0BF723E7-F59F-41BC-A557-DAE88251D7B9}

Dropping Routine

This Trojan drops the following files:

  • %Application Data%\newtab\newtab.exe
  • %Application Data%\newtab\newtab32.dll
  • %Application Data%\newtab\newtab64.dll
  • %Application Data%\newtab\newtabdel.exe
  • %Application Data%\newtab\newtabin.exe

(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Roaming on Windows Vista and 7.)

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine: 9.300

Step 1

Before doing any scans, Windows XP, Windows Vista, and Windows 7 users must disable System Restore to allow full scanning of their computers.

Step 2

Restart in Safe Mode

[ Learn More ]

Step 3

Close all opened browser windows

Step 4

Delete this registry key

[ 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_CURRENT_USER\Software\Microsoft\Internet Explorer
    • TabbedBrowsing
  • In HKEY_CURRENT_USER\Software
    • _newtab
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Uninstall
    • newtab
  • In HKEY_CLASSES_ROOT\CLSID
    • {36936EFC-0B55-4DF4-A01D-69CD27B4309E}
  • In HKEY_CLASSES_ROOT\CLSID\{36936EFC-0B55-4DF4-A01D-69CD27B4309E}
    • InprocServer32

Step 5

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_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • newtab = "%Application Data%\newtab\newtab.exe"
  • In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\TabbedBrowsing
    • Enabled = "1"
  • In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\TabbedBrowsing
    • NewTabPageShow = "0"
  • In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main
    • Enable Browser Extensions = "yes"
  • In HKEY_CURRENT_USER\Software\_newtab
    • User = "68AD0FD0_1922168568153"
  • In HKEY_CURRENT_USER\Software\_newtab
    • Partner = "newtab"
  • In HKEY_CURRENT_USER\Software\_newtab
    • sendlog = "20130530"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Uninstall\newtab
    • DisplayIcon = "%Application Data%\newtab\newtabdel.exe.exe,0"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Uninstall\newtab
    • DisplayName = "newtab"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Uninstall\newtab
    • UninstallString = "%Application Data%\newtab\newtabdel.exe"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{36936EFC-0B55-4DF4-A01D-69CD27B4309E}\InprocServer32
    • ThreadingModel = "Apartment"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Browser Helper Objects\{36936EFC-0B55-4DF4-A01D-69CD27B4309E}
    • NoExplorer = "1"

Step 6

Search and delete these components

[ Learn More ]
There may be some components 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.
  • %Application Data%\newtab\newtab.exe
  • %Application Data%\newtab\newtab32.dll
  • %Application Data%\newtab\newtab64.dll
  • %Application Data%\newtab\newtabdel.exe
  • %Application Data%\newtab\newtabin.exe

Step 7

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.
  • %Application Data%\newtab

Step 8

Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_CLICKR.UP. 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 these deleted registry keys/values from backup

*Note: Only Microsoft-related keys/values will be restored. If the malware/grayware also deleted registry keys/values related to programs that are not from Microsoft, please reinstall those programs on your computer.

  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Ext\Settings
    • {36936EFC-0B55-4DF4-A01D-69CD27B4309E}
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Ext\Settings
    • {0BF723E7-F59F-41BC-A557-DAE88251D7B9}


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