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BKDR_TDSS.SMA

December 04, 2013
 ALIASES:

Trojan:Win32/Alureon.CT (Microsoft); :TDSS.c (McAfee); Adware.ADH (Symantec); ARC:Rsrc-Package, ARC:[data0000.cab]:CAB, [data0000.cab/codec.exe]:Packed.Win32.TDSS.aa, ARC:[data00 (Kaspersky); Trojan.Win32.Alureon.bk (v) (Sunbelt)

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW


This backdoor 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:

281,729 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

08 Oct 2011

Arrival Details

This backdoor 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 backdoor creates the following folders:

  • %User Temp%\IXP000.TMP
  • %Program Files%\WorldUnlock Codes Calculator
  • %System Root%\Documents and Settings
  • %System Root%\Documents and Settings\Administrator
  • %Start Menu%\Programs
  • %Start Menu%\Programs\WorldUnlock Calculator

(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).. %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.. %Start Menu% is the current user's Start Menu folder, which is usually C:\Windows\Start Menu or C:\Documents and Settings\{User name}\Start Menu on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Roaming\Microsoft\Windows\Start Menu on Windows Vista and 7.)

Autostart Technique

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\RunOnce
wextract_cleanup0 = "rundll32.exe %System%\advpack.dll,DelNodeRunDLL32 "%User Temp%\IXP000.TMP\""

Other System Modifications

This backdoor deletes the following files:

  • %User Temp%\IXP000.TMP\WorldUnlock_v44_Setup.exe
  • %User Temp%\IXP000.TMP\codec.exe
  • %System%\spool\PRTPROCS\W32X86\1.tmp
  • %User Temp%\nsc4.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.. %System% is the Windows system folder, which is usually C:\Windows\System32.)

It deletes the following folders:

  • %User Temp%\IXP000.TMP
  • %User Temp%\IXP000.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_LOCAL_MACHINE\SOFTWARE\WorldUnlock Codes Calculator

HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows\CurrentVersion\Uninstall\
WorldUnlock Codes Calculator

It adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\WorldUnlock Codes Calculator
Install_Dir = "%Program Files%\WorldUnlock Codes Calculator"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
WorldUnlock Codes Calculator
DisplayName = "WorldUnlock Codes Calculator"

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

Dropping Routine

This backdoor drops the following files:

  • %User Temp%\IXP000.TMP\TMP4351$.TMP
  • %User Temp%\IXP000.TMP\codec.exe
  • %User Temp%\IXP000.TMP\WorldUnlock_v44_Setup.exe
  • %Program Files%\WorldUnlock Codes Calculator\WorldUnlock_Calc.exe
  • %Program Files%\WorldUnlock Codes Calculator\dctx.dll
  • %Program Files%\WorldUnlock Codes Calculator\mc.dll
  • %Program Files%\WorldUnlock Codes Calculator\provider.txt
  • %Program Files%\WorldUnlock Codes Calculator\gid1.txt
  • %Program Files%\WorldUnlock Codes Calculator\_WorldUnlock_Calc.exe.manifest
  • %Start Menu%\Programs\WorldUnlock Calculator\WorldUnlock Calculator.lnk
  • %Start Menu%\Programs\WorldUnlock Calculator\Uninstall.lnk
  • %Program Files%\WorldUnlock Codes Calculator\uninst.exe
  • %System%\spool\PRTPROCS\W32X86\1.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.. %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).. %Start Menu% is the current user's Start Menu folder, which is usually C:\Windows\Start Menu or C:\Documents and Settings\{User name}\Start Menu on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Roaming\Microsoft\Windows\Start Menu on Windows Vista and 7.. %System% is the Windows system folder, which is usually C:\Windows\System32.)

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine:

9.200

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\SOFTWARE
    • WorldUnlock Codes Calculator
  • In HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Uninstall
    • WorldUnlock Codes Calculator

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_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\RunOnce
    • wextract_cleanup0="rundll32.exe %System%\advpack.dll,DelNodeRunDLL32 "%User Temp%\IXP000.TMP\""
  • In HKEY_LOCAL_MACHINE\SOFTWARE\WorldUnlock Codes Calculator
    • Install_Dir="%Program Files%\WorldUnlock Codes Calculator"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\WorldUnlock Codes Calculator
    • DisplayName="WorldUnlock Codes Calculator"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\WorldUnlock Codes Calculator
    • UninstallString=""%Program Files%\WorldUnlock Codes Calculator\uninst.exe""

Step 5

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.
  • %User Temp%\IXP000.TMP
  • %Program Files%\WorldUnlock Codes Calculator
  • %System Root%\Documents and Settings
  • %System Root%\Documents and Settings\Administrator
  • %Start Menu%\Programs
  • %Start Menu%\Programs\WorldUnlock Calculator

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%\IXP000.TMP\TMP4351$.TMP
  • %User Temp%\IXP000.TMP\codec.exe
  • %User Temp%\IXP000.TMP\WorldUnlock_v44_Setup.exe
  • %Program Files%\WorldUnlock Codes Calculator\WorldUnlock_Calc.exe
  • %Program Files%\WorldUnlock Codes Calculator\dctx.dll
  • %Program Files%\WorldUnlock Codes Calculator\mc.dll
  • %Program Files%\WorldUnlock Codes Calculator\provider.txt
  • %Program Files%\WorldUnlock Codes Calculator\gid1.txt
  • %Program Files%\WorldUnlock Codes Calculator\_WorldUnlock_Calc.exe.manifest
  • %Start Menu%\Programs\WorldUnlock Calculator\WorldUnlock Calculator.lnk
  • %Start Menu%\Programs\WorldUnlock Calculator\Uninstall.lnk
  • %Program Files%\WorldUnlock Codes Calculator\uninst.exe
  • %System%\spool\PRTPROCS\W32X86\1.tmp

Step 7

Restart in normal mode and scan your computer with your Trend Micro product for files detected as BKDR_TDSS.SMA. 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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