TROJ_ADH.USAV0109

May 20, 2013
 ALIASES:

Generic PUP.x!zb. (McAfee); Trojan.ADH.2 (Symantec); AdWare.Win32.SideTab.ar (Kaspersky); Trojan.Win32.Generic!BT (Sunbelt); Trojan horse Generic27.AMZK (AVG)

 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.

It deletes itself after execution.

  TECHNICAL DETAILS

File Size:

278,116 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

20 May 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:

  • %System Root%\DOCUME~1
  • %System Root%\DOCUME~1\Wilbert
  • %User Profile%\LOCALS~1
  • %User Temp%\nst3.tmp
  • %Program Files%\SmartTool
  • %User Temp%\nsf14.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:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.. %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, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista and 7.. %Program Files% is the default Program Files folder, usually C:\Program Files in Windows 2000, Server 2003, and XP (32-bit), Vista (32-bit), and 7 (32-bit), or C:\Program Files (x86) in Windows XP (64-bit), Vista (64-bit), and 7 (64-bit).)

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
SmartTool = "%Program Files%\SmartTool\SmartTool.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\{2D891923-34B7-4186-9B47-752624535DC1}

Other System Modifications

This Trojan deletes the following files:

  • %User Temp%\nsd1.tmp
  • %User Temp%\nst3.tmp
  • %User Temp%\nsq12.tmp
  • %User Temp%\nsf14.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, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista and 7.)

It adds the following registry keys:

HKEY_CURRENT_USER\Software\SmartTool

HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows\CurrentVersion\Uninstall\
SmartTool

HKEY_CLASSES_ROOT\SmartTool.SmartToolCtl.1

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
SmartTool.SmartToolCtl.1\CLSID

HKEY_CLASSES_ROOT\SmartTool.SmartToolCtl

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
SmartTool.SmartToolCtl\CLSID

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
SmartTool.SmartToolCtl\CurVer

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{2D891923-34B7-4186-9B47-752624535DC1}

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{2D891923-34B7-4186-9B47-752624535DC1}\ProgID

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{2D891923-34B7-4186-9B47-752624535DC1}\VersionIndependentProgID

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{2D891923-34B7-4186-9B47-752624535DC1}\Programmable

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{2D891923-34B7-4186-9B47-752624535DC1}\InprocServer32

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{2D891923-34B7-4186-9B47-752624535DC1}\TypeLib

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
TypeLib\{E97662C9-6D8A-47A6-BBF6-17730FEE28F0}

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
TypeLib\{E97662C9-6D8A-47A6-BBF6-17730FEE28F0}\1.0

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
TypeLib\{E97662C9-6D8A-47A6-BBF6-17730FEE28F0}\1.0\
FLAGS

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
TypeLib\{E97662C9-6D8A-47A6-BBF6-17730FEE28F0}\1.0\
0

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
TypeLib\{E97662C9-6D8A-47A6-BBF6-17730FEE28F0}\1.0\
0\win32

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
TypeLib\{E97662C9-6D8A-47A6-BBF6-17730FEE28F0}\1.0\
HELPDIR

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Interface\{0F67A437-3336-4B2E-B211-D5BD3C6F5461}

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Interface\{0F67A437-3336-4B2E-B211-D5BD3C6F5461}\ProxyStubClsid

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Interface\{0F67A437-3336-4B2E-B211-D5BD3C6F5461}\ProxyStubClsid32

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Interface\{0F67A437-3336-4B2E-B211-D5BD3C6F5461}\TypeLib

It adds the following registry entries:

HKEY_CURRENT_USER\Software\SmartTool
id = "SM90"

HKEY_CURRENT_USER\Software\SmartTool
version = "1.0.0.6"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
SmartTool
DisplayName = "SmartTool"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
SmartTool
UninstallString = "%Program Files%\SmartTool\Uninstall.exe"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
SmartTool
NoModify = "1"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
SmartTool
NoRepair = "1"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{2D891923-34B7-4186-9B47-752624535DC1}\InprocServer32
ThreadingModel = "Apartment"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Interface\{0F67A437-3336-4B2E-B211-D5BD3C6F5461}\TypeLib
Version = "1.0"

HKEY_CURRENT_USER\Software\SmartTool
sp = "20130517220305"

HKEY_CURRENT_USER\Software\SmartTool
version = "1.0.0.8"

HKEY_CURRENT_USER\Software\SmartTool
sp = "20130517220351"

Dropping Routine

This Trojan drops the following files:

  • %User Temp%\nst3.tmp\nsProcess.dll
  • %User Temp%\nst3.tmp\UAC.dll
  • %Program Files%\SmartTool\SmartTool.dll
  • %Program Files%\SmartTool\SmartTool.exe
  • %Program Files%\SmartTool\adc.acc
  • %Program Files%\SmartTool\Uninstall.exe
  • %User Temp%\nst3.tmp\IpConfig.dll
  • %User Temp%\nst3.tmp\NSISdl.dll
  • %User Temp%\inst.xxx
  • %User Temp%\nst3.tmp\SelfDel.dll
  • %User Temp%\SMU1008.exe
  • %User Temp%\nsf14.tmp\UAC.dll
  • %User Temp%\nsf14.tmp\fct.dll
  • %User Temp%\nsf14.tmp\nsProcess.dll
  • %User Temp%\nsf14.tmp\IpConfig.dll
  • %User Temp%\nsf14.tmp\NSISdl.dll

(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, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista and 7.. %Program Files% is the default Program Files folder, usually C:\Program Files in Windows 2000, Server 2003, and XP (32-bit), Vista (32-bit), and 7 (32-bit), or C:\Program Files (x86) in Windows XP (64-bit), Vista (64-bit), and 7 (64-bit).)

Other Details

This Trojan connects to the following possibly malicious URL:

  • http://sm.{BLOCKED}b.co.kr/update/SM90/SmartTool.ini
  • http://sm.{BLOCKED}b.co.kr/update/SM90/SMU1008.exe

It deletes itself after execution.

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
    • SmartTool
  • In HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Uninstall
    • SmartTool
  • In HKEY_CLASSES_ROOT
    • SmartTool.SmartToolCtl.1
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\SmartTool.SmartToolCtl.1
    • CLSID
  • In HKEY_CLASSES_ROOT
    • SmartTool.SmartToolCtl
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\SmartTool.SmartToolCtl
    • CLSID
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\SmartTool.SmartToolCtl
    • CurVer
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID
    • {2D891923-34B7-4186-9B47-752624535DC1}
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{2D891923-34B7-4186-9B47-752624535DC1}
    • ProgID
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{2D891923-34B7-4186-9B47-752624535DC1}
    • VersionIndependentProgID
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{2D891923-34B7-4186-9B47-752624535DC1}
    • Programmable
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{2D891923-34B7-4186-9B47-752624535DC1}
    • InprocServer32
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{2D891923-34B7-4186-9B47-752624535DC1}
    • TypeLib
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\TypeLib
    • {E97662C9-6D8A-47A6-BBF6-17730FEE28F0}
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\TypeLib\{E97662C9-6D8A-47A6-BBF6-17730FEE28F0}
    • 1.0
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\TypeLib\{E97662C9-6D8A-47A6-BBF6-17730FEE28F0}\1.0
    • FLAGS
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\TypeLib\{E97662C9-6D8A-47A6-BBF6-17730FEE28F0}\1.0
    • 0
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\TypeLib\{E97662C9-6D8A-47A6-BBF6-17730FEE28F0}\1.0\0
    • win32
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\TypeLib\{E97662C9-6D8A-47A6-BBF6-17730FEE28F0}\1.0
    • HELPDIR
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Interface
    • {0F67A437-3336-4B2E-B211-D5BD3C6F5461}
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Interface\{0F67A437-3336-4B2E-B211-D5BD3C6F5461}
    • ProxyStubClsid
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Interface\{0F67A437-3336-4B2E-B211-D5BD3C6F5461}
    • ProxyStubClsid32
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Interface\{0F67A437-3336-4B2E-B211-D5BD3C6F5461}
    • TypeLib

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_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • SmartTool = "%Program Files%\SmartTool\SmartTool.exe"
  • In HKEY_CURRENT_USER\Software\SmartTool
    • id = "SM90"
  • In HKEY_CURRENT_USER\Software\SmartTool
    • version = "1.0.0.6"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\SmartTool
    • DisplayName = "SmartTool"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\SmartTool
    • UninstallString = "%Program Files%\SmartTool\Uninstall.exe"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\SmartTool
    • NoModify = "1"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\SmartTool
    • NoRepair = "1"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{2D891923-34B7-4186-9B47-752624535DC1}\InprocServer32
    • ThreadingModel = "Apartment"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Interface\{0F67A437-3336-4B2E-B211-D5BD3C6F5461}\TypeLib
    • Version = "1.0"
  • In HKEY_CURRENT_USER\Software\SmartTool
    • sp = "20130517220305"
  • In HKEY_CURRENT_USER\Software\SmartTool
    • version = "1.0.0.8"
  • In HKEY_CURRENT_USER\Software\SmartTool
    • sp = "20130517220351"

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.
  • %User Temp%\nst3.tmp\nsProcess.dll
  • %User Temp%\nst3.tmp\UAC.dll
  • %Program Files%\SmartTool\SmartTool.dll
  • %Program Files%\SmartTool\SmartTool.exe
  • %Program Files%\SmartTool\adc.acc
  • %Program Files%\SmartTool\Uninstall.exe
  • %User Temp%\nst3.tmp\IpConfig.dll
  • %User Temp%\nst3.tmp\NSISdl.dll
  • %User Temp%\inst.xxx
  • %User Temp%\nst3.tmp\SelfDel.dll
  • %User Temp%\SMU1008.exe
  • %User Temp%\nsf14.tmp\UAC.dll
  • %User Temp%\nsf14.tmp\fct.dll
  • %User Temp%\nsf14.tmp\nsProcess.dll
  • %User Temp%\nsf14.tmp\IpConfig.dll
  • %User Temp%\nsf14.tmp\NSISdl.dll

Step 7

Search and delete these folders

[ 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.
  • %System Root%\DOCUME~1
  • %System Root%\DOCUME~1\Wilbert
  • %User Profile%\LOCALS~1
  • %User Temp%\nst3.tmp
  • %Program Files%\SmartTool
  • %User Temp%\nsf14.tmp

Step 8

Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_ADH.USAV0109. 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%\nsd1.tmp
  • %User Temp%\nst3.tmp
  • %User Temp%\nsq12.tmp
  • %User Temp%\nsf14.tmp


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