ALIASES:

Backdoor:Win32/Poison.E (Microsoft); Downloader (Symantec); Backdoor.Win32.Inject.xfa (Kaspersky); Trojan.Win32.Generic!BT (Sunbelt)

 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: 403,456 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 01 Mar 2012

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:

  • %User Temp%\Adobe

(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.)

Autostart Technique

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Active Setup\Installed Components\{DEEB6634-94F3-CBE5-CBD2-66E02119AFC4}
StubPath = "%System%:csentomder.exe"

Other System Modifications

This Trojan deletes the following files:

  • %User Temp%\~TX2.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\Local AppWizard-Generated Applications

HKEY_CURRENT_USER\Software\Local AppWizard-Generated Applications\

HKEY_CURRENT_USER\Software\Local AppWizard-Generated Applications\
Recent File List

HKEY_CURRENT_USER\Software\Local AppWizard-Generated Applications\
Settings

HKEY_CURRENT_USER\Software\Adobe\
Adobe Acrobat\10.0

HKEY_CURRENT_USER\Software\Adobe\
Adobe Synchronizer\10.0

HKEY_LOCAL_MACHINE\System\Acrobatbrokerserverdispatchercpp789

HKEY_LOCAL_MACHINE\Software\Microsoft\
Active Setup\Installed Components\{DEEB6634-94F3-CBE5-CBD2-66E02119AFC4}

HKEY_CURRENT_USER\Software\Adobe\
Acrobat Reader\10.0\Installer\
Migrated

It deletes the following registry keys:

HKEY_CURRENT_USER\Software\Microsoft\
Active Setup\Installed Components\{DEEB6634-94F3-CBE5-CBD2-66E02119AFC4}

Dropping Routine

This Trojan drops the following files:

  • %System Root%\{malware file name}.bat
  • %System%:csentomder.exe

(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.. %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_CURRENT_USER\Software
    • Local AppWizard-Generated Applications
  • In HKEY_CURRENT_USER\Software\Local AppWizard-Generated Applications
  • In HKEY_CURRENT_USER\Software\Local AppWizard-Generated Applications
    • Recent File List
  • In HKEY_CURRENT_USER\Software\Local AppWizard-Generated Applications
    • Settings
  • In HKEY_CURRENT_USER\Software\Adobe\Adobe Acrobat
    • 10.0
  • In HKEY_CURRENT_USER\Software\Adobe\Adobe Synchronizer
    • 10.0
  • In HKEY_LOCAL_MACHINE\System
    • Acrobatbrokerserverdispatchercpp789
  • In HKEY_LOCAL_MACHINE\Software\Microsoft\Active Setup\Installed Components
    • {DEEB6634-94F3-CBE5-CBD2-66E02119AFC4}
  • In HKEY_CURRENT_USER\Software\Adobe\Acrobat Reader\10.0\Installer
    • Migrated

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\Active Setup\Installed Components\{DEEB6634-94F3-CBE5-CBD2-66E02119AFC4}
    • StubPath = "%System%:csentomder.exe"

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.
  • %System Root%\{malware file name}.bat
  • %System%:csentomder.exe

Step 6

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 Temp%\Adobe

Step 7

Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_BIND32.SMEP. 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%\~TX2.tmp

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\Active Setup\Installed Components
    • {DEEB6634-94F3-CBE5-CBD2-66E02119AFC4}

Step 10

Scan your computer with your Trend Micro product to delete files detected as TROJ_BIND32.SMEP. 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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