TROJ_ESTIWIR.R


 ALIASES:

Trojan:Win32/Estiwir (Microsoft); Trojan.Packed.NsAnti (Symantec); HEUR:Trojan.Win32.Generic (Kaspersky); Trojan-Dropper.Win32.OnlineGames.qcf (v) (Sunbelt); Win32/Heur (AVG)

 PLATFORM:

Windows

 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:

1,321,490 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

10 Jan 2015

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 drops the following copies of itself into the affected system:

  • %User Temp%\95b8.tmp

(Note: %User Temp% is the user's temporary folder, where it usually is C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local\Temp on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.)

It creates the following folders:

  • %System Root%\DOCUME~1
  • %System Root%\DOCUME~1\Wilbert
  • %User Profile%\LOCALS~1
  • %User Temp%\nsd6.tmp
  • %Program Files%\smarttip
  • %User Temp%\yhsys
  • %User Temp%\nsg27.tmp
  • %Program Files%\SmartTip

(Note: %System Root% is the Windows root folder, where it usually is C:\ on all Windows operating system versions.. %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 user's temporary folder, where it usually is C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local\Temp on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.. %Program Files% is the Program Files folder, where it usually is C:\Program Files on all Windows operating system versions; C:\Program Files (x86) for 32-bit applications running on Windows 64-bit operating systems.)

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
smarttip = "%Program Files%\smarttip\SmartTipC.exe /RUN"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
SmartTip = "%Program Files%\SmartTip\SmartTipAgent.exe"

It registers as a system service to ensure its automatic execution at every system startup by adding the following registry keys:

HKEY_LOCAL_MACHINE\System\CurrentControlSet\
Services\50664b2f

Other System Modifications

This Trojan deletes the following files:

  • %User Temp%\nsn4.tmp
  • %User Temp%\nsd6.tmp
  • %User Profile%\Cookies\index.dat
  • %System%\Drivers\EstRtw.sys
  • %User Temp%\9990.exe
  • %User Temp%\nsq25.tmp
  • %User Temp%\nsg27.tmp
  • %Program Files%\SmartTip\SmartTipC.exe
  • %Program Files%\SmartTip\Uninstall.exe
  • %Program Files%\SmartTip\Update.dat
  • %User Temp%\68546.exe
  • %System Root%\DelUS.bat

(Note: %User Temp% is the user's temporary folder, where it usually is C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local\Temp on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.. %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.. %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.. %Program Files% is the Program Files folder, where it usually is C:\Program Files on all Windows operating system versions; C:\Program Files (x86) for 32-bit applications running on Windows 64-bit operating systems.. %System Root% is the Windows root folder, where it usually is C:\ on all Windows operating system versions.)

It adds the following registry keys:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Uninstall\
½º¸¶Æ®ÆÁ(SmartTip)

HKEY_CLASSES_ROOT\CLSID\HOOK_ID

HKEY_CLASSES_ROOT\CLSID\SYS_DLL

HKEY_CURRENT_USER\Software\SmartTip

HKEY_CURRENT_USER\Software\SmartTip\
update

HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows\CurrentVersion\Uninstall\
SmartTip

It adds the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Uninstall\
½º¸¶Æ®ÆÁ(SmartTip)
DisplayName = "½º¸¶Æ®ÆÁ(SmartTip)"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Uninstall\
½º¸¶Æ®ÆÁ(SmartTip)
InstallLocation = "%Program Files%\smarttip"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Uninstall\
½º¸¶Æ®ÆÁ(SmartTip)
UninstallString = "%Program Files%\smarttip\Uninstall.exe"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Uninstall\
½º¸¶Æ®ÆÁ(SmartTip)
DisplayIcon = "%Program Files%\smarttip\SmartTipC.exe"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Uninstall\
½º¸¶Æ®ÆÁ(SmartTip)
DisplayVersion = "1.0.0.1"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Uninstall\
½º¸¶Æ®ÆÁ(SmartTip)
URLInfoAbout = "http://smarttip.{BLOCKED}o.kr"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Uninstall\
½º¸¶Æ®ÆÁ(SmartTip)
Publisher = "TGSM"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\HOOK_ID
name = "9990.exe"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\50664b2f
Type = "1"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\50664b2f
ErrorControl = "1"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\50664b2f
Start = "1"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\50664b2f
ImagePath = "\??\%System%\drivers\50664b2f.sys"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\SYS_DLL
name = "UugdrGY.dll"

HKEY_CURRENT_USER\Software\SmartTip
dir = "%Program Files%\SmartTip"

HKEY_CURRENT_USER\Software\SmartTip\
update
ver = "7"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
SmartTip
Comments = "SmartTip"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
SmartTip
DisplayIcon = "%Program Files%\SmartTip\uninst.exe"

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
SmartTip
DisplayVersion = "7"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
SmartTip
HelpLink = "http://www.{BLOCKED}ip.co.kr"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
SmartTip
Publisher = "Maroin"

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
SmartTip
URLInfoAbout = "http://www.{BLOCKED}ip.co.kr"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
SmartTip
URLUpdateInfo = "http://www.{BLOCKED}ip.co.kr"

It deletes the following registry keys:

HKEY_CLASSES_ROOT\CLSID\TANG2_OTP

HKEY_CLASSES_ROOT\CLSID\HOK_OTP

HKEY_CLASSES_ROOT\CLSID\TANG1_NCP

HKEY_CLASSES_ROOT\CLSID\TANG1_URL

HKEY_CLASSES_ROOT\CLSID\AH3SEC

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Explorer\
Browser Helper Objects\{18DF081C-E8AD-4283-A596-FA578C2EBDC3}

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Explorer\
Browser Helper Objects

HKEY_LOCAL_MACHINE\System\CurrentControlSet\
Services\50664b2f\Enum

HKEY_LOCAL_MACHINE\System\CurrentControlSet\
Services\50664b2f\Security

Dropping Routine

This Trojan drops the following files:

  • %User Temp%\9990.exe
  • %User Temp%\nsd6.tmp\System.dll
  • %User Temp%\license1.txt
  • %User Temp%\nsd6.tmp\KillProcDLL.dll
  • %Program Files%\smarttip\SmartTipC.exe
  • %Program Files%\smarttip\Uninstall.exe
  • %User Temp%\nsd6.tmp\version.dll
  • %User Temp%\A1.zip
  • %User Temp%\B1.zip
  • %User Temp%\C1.zip
  • %User Temp%\D1.zip
  • %User Temp%\yhsys\doit.rar
  • %System%\drivers\50664b2f.sys
  • %User Temp%\stdJqw.dll
  • %User Temp%\UugdrGY.dll
  • %User Temp%\gu9qdCwJFD.dll
  • %User Temp%\68546.exe
  • %Program Files%\smarttip\Update.dat
  • %User Temp%\nsg27.tmp\KillProcDLL.dll
  • %User Temp%\nsg27.tmp\DLLWaitForKillProgram.dll
  • %User Temp%\nsg27.tmp\nsExec.dll
  • %User Temp%\nsg27.tmp\DLLWebCount.dll
  • %Program Files%\SmartTip\SmartTip.exe
  • %Program Files%\SmartTip\SmartTipAgent.exe
  • %Program Files%\SmartTip\smarttip.dll
  • %User Temp%\nsg27.tmp\GetVersion.dll
  • %Program Files%\SmartTip\uninst.exe
  • %User Temp%\nsg27.tmp\SelfDelete.dll
  • \DelUS.bat
  • %System%\ws2tcpip.dll

(Note: %User Temp% is the user's temporary folder, where it usually is C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local\Temp on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.. %Program Files% is the Program Files folder, where it usually is C:\Program Files on all Windows operating system versions; C:\Program Files (x86) for 32-bit applications running on Windows 64-bit operating systems.. %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.)

Other Details

This Trojan connects to the following possibly malicious URL:

  • http://sub.{BLOCKED}ip.co.kr/opapp/tdisk/app/download/{BLOCKED}ip_silent.exe
  • http://{BLOCKED}9.167.187/mail.asp?{random characters}
  • http://smarttip.{BLOCKED}o.kr
  • http://smarttip.{BLOCKED}o.kr/mmsv/Access3.php?{random characters}
  • {BLOCKED}.1.211
  • {BLOCKED}0.1
  • {BLOCKED}.1.209

It deletes itself after execution.

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine:

9.700

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

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_LOCAL_MACHINE\System\CurrentControlSet\Services
    • 50664b2f
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Uninstall
    • ½º¸¶Æ®ÆÁ(SmartTip)
  • In HKEY_CLASSES_ROOT\CLSID
    • HOOK_ID
  • In HKEY_CLASSES_ROOT\CLSID
    • SYS_DLL
  • In HKEY_CURRENT_USER\Software
    • SmartTip
  • In HKEY_CURRENT_USER\Software\SmartTip
    • update
  • In HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Uninstall
    • SmartTip

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_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • smarttip = "%Program Files%\smarttip\SmartTipC.exe /RUN"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • SmartTip = "%Program Files%\SmartTip\SmartTipAgent.exe"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Uninstall\½º¸¶Æ®ÆÁ(SmartTip)
    • DisplayName = "½º¸¶Æ®ÆÁ(SmartTip)"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Uninstall\½º¸¶Æ®ÆÁ(SmartTip)
    • InstallLocation = "%Program Files%\smarttip"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Uninstall\½º¸¶Æ®ÆÁ(SmartTip)
    • UninstallString = "%Program Files%\smarttip\Uninstall.exe"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Uninstall\½º¸¶Æ®ÆÁ(SmartTip)
    • DisplayIcon = "%Program Files%\smarttip\SmartTipC.exe"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Uninstall\½º¸¶Æ®ÆÁ(SmartTip)
    • DisplayVersion = "1.0.0.1"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Uninstall\½º¸¶Æ®ÆÁ(SmartTip)
    • URLInfoAbout = "http://smarttip.{BLOCKED}o.kr"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Uninstall\½º¸¶Æ®ÆÁ(SmartTip)
    • Publisher = "TGSM"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\HOOK_ID
    • name = "9990.exe"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\50664b2f
    • Type = "1"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\50664b2f
    • ErrorControl = "1"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\50664b2f
    • Start = "1"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\50664b2f
    • ImagePath = "\??\%System%\drivers\50664b2f.sys"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\SYS_DLL
    • name = "UugdrGY.dll"
  • In HKEY_CURRENT_USER\Software\SmartTip
    • dir = "%Program Files%\SmartTip"
  • In HKEY_CURRENT_USER\Software\SmartTip\update
    • ver = "7"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\SmartTip
    • Comments = "SmartTip"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\SmartTip
    • DisplayIcon = "%Program Files%\SmartTip\uninst.exe"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\SmartTip
    • DisplayName = "Windows SmartTip"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\SmartTip
    • DisplayVersion = "7"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\SmartTip
    • HelpLink = "http://www.{BLOCKED}ip.co.kr"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\SmartTip
    • Publisher = "Maroin"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\SmartTip
    • UninstallString = "%Program Files%\SmartTip\uninst.exe"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\SmartTip
    • URLInfoAbout = "http://www.{BLOCKED}ip.co.kr"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\SmartTip
    • URLUpdateInfo = "http://www.{BLOCKED}ip.co.kr"

Step 5

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%\9990.exe
  • %User Temp%\nsd6.tmp\System.dll
  • %User Temp%\license1.txt
  • %User Temp%\nsd6.tmp\KillProcDLL.dll
  • %Program Files%\smarttip\SmartTipC.exe
  • %Program Files%\smarttip\Uninstall.exe
  • %User Temp%\nsd6.tmp\version.dll
  • %User Temp%\A1.zip
  • %User Temp%\B1.zip
  • %User Temp%\C1.zip
  • %User Temp%\D1.zip
  • %User Temp%\yhsys\doit.rar
  • %System%\drivers\50664b2f.sys
  • %User Temp%\stdJqw.dll
  • %User Temp%\UugdrGY.dll
  • %User Temp%\gu9qdCwJFD.dll
  • %User Temp%\68546.exe
  • %Program Files%\smarttip\Update.dat
  • %User Temp%\nsg27.tmp\KillProcDLL.dll
  • %User Temp%\nsg27.tmp\DLLWaitForKillProgram.dll
  • %User Temp%\nsg27.tmp\nsExec.dll
  • %User Temp%\nsg27.tmp\DLLWebCount.dll
  • %Program Files%\SmartTip\SmartTip.exe
  • %Program Files%\SmartTip\SmartTipAgent.exe
  • %Program Files%\SmartTip\smarttip.dll
  • %User Temp%\nsg27.tmp\GetVersion.dll
  • %Program Files%\SmartTip\uninst.exe
  • %User Temp%\nsg27.tmp\SelfDelete.dll
  • \DelUS.bat
  • %System%\ws2tcpip.dll

Step 6

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%\nsd6.tmp
  • %Program Files%\smarttip
  • %User Temp%\yhsys
  • %User Temp%\nsg27.tmp
  • %Program Files%\SmartTip

Step 7

Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_ESTIWIR.R. 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 8

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%\nsn4.tmp
  • %User Temp%\nsd6.tmp
  • %User Profile%\Cookies\index.dat
  • %System%\Drivers\EstRtw.sys
  • %User Temp%\9990.exe
  • %User Temp%\nsq25.tmp
  • %User Temp%\nsg27.tmp
  • %Program Files%\SmartTip\SmartTipC.exe
  • %Program Files%\SmartTip\Uninstall.exe
  • %Program Files%\SmartTip\Update.dat
  • %User Temp%\68546.exe
  • %System Root%\DelUS.bat

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_CLASSES_ROOT\CLSID
    • TANG2_OTP
  • In HKEY_CLASSES_ROOT\CLSID
    • HOK_OTP
  • In HKEY_CLASSES_ROOT\CLSID
    • TANG1_NCP
  • In HKEY_CLASSES_ROOT\CLSID
    • TANG1_URL
  • In HKEY_CLASSES_ROOT\CLSID
    • AH3SEC
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Browser Helper Objects
    • {18DF081C-E8AD-4283-A596-FA578C2EBDC3}
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer
    • Browser Helper Objects
  • In HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\50664b2f
    • Enum
  • In HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\50664b2f
    • Security


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