TROJ_DROPPE.TW


 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:

428,641 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

13 Dec 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%\ѧϰʵ¼ùÖйúÅ©Òµ¿Æѧ·¢Õ¹¹Û¼°¿ª´´ÐÂÊÀ´úÅ©¾­¹¤×÷оÖÃæ

(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.)

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\{ADEF456S-CRGS-DG53-8427-45182378SPDG}
ComponentID = "NMEET Setup"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Active Setup\Installed Components\{ADEF456S-CRGS-DG53-8427-45182378SPDG}
IsInstalled = "1"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Active Setup\Installed Components\{ADEF456S-CRGS-DG53-8427-45182378SPDG}
Locale = "CH"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Active Setup\Installed Components\{ADEF456S-CRGS-DG53-8427-45182378SPDG}
StubPath = "rundll32 %Program Files%\NetMeeting\neqeet.dll,initrun"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Active Setup\Installed Components\{ADEF456S-CRGS-DG53-8427-45182378SPDG}
Version = "5,2,3790,3959"

Other System Modifications

This Trojan deletes the following files:

  • %System Root%\ѧϰʵ¼ùÖйúÅ©Òµ¿Æѧ·¢Õ¹¹Û¼°¿ª´´ÐÂÊÀ´úÅ©¾­¹¤×÷оÖÃæ
  • %System Root%\ѧϰʵ¼ùÖйúÅ©Òµ¿Æѧ·¢Õ¹¹Û¼°¿ª´´ÐÂÊÀ´úÅ©¾­¹¤×÷оÖÃæ\ÂÛÎĸå¼þ.liz
  • %Windows%\Help\ѧϰʵ¼ùÖйúÅ©Òµ¿Æѧ·¢Õ¹¹Û¼°¿ª´´ÐÂÊÀ´úÅ©¾­¹¤×÷оÖÃæ.bak
  • %User Temp%\t2.exe
  • %User Temp%\byeyou.tmp
  • %Windows%\~update.dll
  • %Program Files%\NetMeeting\neqmeet.exe

(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.. %Windows% is the Windows folder, which is usually C:\Windows.. %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).)

It adds the following registry keys:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Active Setup\Installed Components\{ADEF456S-CRGS-DG53-8427-45182378SPDG}

It deletes the following registry keys:

HKEY_LOCAL_MACHINE\Software\Microsoft\
Active Setup\Installed Components\{ADEF456S-CRGS-DG53-8427-45182378SPDG}

HKEY_CURRENT_USER\Software\Microsoft\
Active Setup\Installed Components\{ADEF456S-CRGS-DG53-8427-45182378SPDG}

Dropping Routine

This Trojan drops the following files:

  • %System Root%\ѧϰʵ¼ùÖйúÅ©Òµ¿Æѧ·¢Õ¹¹Û¼°¿ª´´ÐÂÊÀ´úÅ©¾­¹¤×÷оÖÃæ\ÂÛÎĸå¼þ.doc
  • %Program Files%\NetMeeting\neqeet.dll
  • %Program Files%\NetMeeting\neqmeet.exe

(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.. %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://{BLOCKED}8.221.1/ip.jpg

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

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\Microsoft\Active Setup\Installed Components
    • {ADEF456S-CRGS-DG53-8427-45182378SPDG}

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\{ADEF456S-CRGS-DG53-8427-45182378SPDG}
    • ComponentID = "NMEET Setup"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Active Setup\Installed Components\{ADEF456S-CRGS-DG53-8427-45182378SPDG}
    • IsInstalled = "1"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Active Setup\Installed Components\{ADEF456S-CRGS-DG53-8427-45182378SPDG}
    • Locale = "CH"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Active Setup\Installed Components\{ADEF456S-CRGS-DG53-8427-45182378SPDG}
    • StubPath = "rundll32 %Program Files%\NetMeeting\neqeet.dll,initrun"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Active Setup\Installed Components\{ADEF456S-CRGS-DG53-8427-45182378SPDG}
    • Version = "5,2,3790,3959"

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%\ѧϰʵ¼ùÖйúÅ©Òµ¿Æѧ·¢Õ¹¹Û¼°¿ª´´ÐÂÊÀ´úÅ©¾­¹¤×÷оÖÃæ\ÂÛÎĸå¼þ.doc
  • %Program Files%\NetMeeting\neqeet.dll
  • %Program Files%\NetMeeting\neqmeet.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.
  • %System Root%\ѧϰʵ¼ùÖйúÅ©Òµ¿Æѧ·¢Õ¹¹Û¼°¿ª´´ÐÂÊÀ´úÅ©¾­¹¤×÷оÖÃæ

Step 7

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

  • %System Root%\ѧϰʵ¼ùÖйúÅ©Òµ¿Æѧ·¢Õ¹¹Û¼°¿ª´´ÐÂÊÀ´úÅ©¾­¹¤×÷оÖÃæ
  • %System Root%\ѧϰʵ¼ùÖйúÅ©Òµ¿Æѧ·¢Õ¹¹Û¼°¿ª´´ÐÂÊÀ´úÅ©¾­¹¤×÷оÖÃæ\ÂÛÎĸå¼þ.liz
  • %Windows%\Help\ѧϰʵ¼ùÖйúÅ©Òµ¿Æѧ·¢Õ¹¹Û¼°¿ª´´ÐÂÊÀ´úÅ©¾­¹¤×÷оÖÃæ.bak
  • %User Temp%\t2.exe
  • %User Temp%\byeyou.tmp
  • %Windows%\~update.dll
  • %Program Files%\NetMeeting\neqmeet.exe

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_LOCAL_MACHINE\Software\Microsoft\Active Setup\Installed Components
    • {ADEF456S-CRGS-DG53-8427-45182378SPDG}
  • In HKEY_CURRENT_USER\Software\Microsoft\Active Setup\Installed Components
    • {ADEF456S-CRGS-DG53-8427-45182378SPDG}


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