TROJ_INJECT.CWC


 ALIASES:

Backdoor.Win32.Zegost.ssr (Kaspersky); Trojan horse Generic31.ACFR (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.

  TECHNICAL DETAILS

File Size:

340,480 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

21 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 drops the following copies of itself into the affected system:

  • %User Profile%\Application Data\FacbookUpdate.exe
  • A:\rundll32.exe

(Note: %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.)

It creates the following folders:

  • %User Temp%\AppLaunch
  • %Program Files%\Iefg

(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).)

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
FacbookUpdate = "%User Profile%\Application Data\FacbookUpdate.exe"

Other System Modifications

This Trojan modifies the following file(s):

  • %Application Data%\GDIPFONTCACHEV1.DAT

(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Roaming on Windows Vista and 7.)

It deletes the following files:

  • %System%\syslog.dat
  • %Program Files%\Iefg\Nefghijkl.pic
  • %System Root%\system32.txt
  • %User Temp%\AppLaunch\Service.exe

(Note: %System% is the Windows system folder, which is usually C:\Windows\System32.. %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.. %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\149431839

HKEY_LOCAL_MACHINE\SOFTWARE\149431839\
Parameters

HKEY_LOCAL_MACHINE\SOFTWARE\108665580

HKEY_LOCAL_MACHINE\SOFTWARE\139665270

HKEY_LOCAL_MACHINE\SOFTWARE\201475763

It adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\149431839\
Parameters
ServiceDll = "%Program Files%\Iefg\Nefghijkl.pic"

HKEY_LOCAL_MACHINE\SOFTWARE\108665580
imgsvc = "StiSvc,Defghi Klmnopqr Tuv"

HKEY_LOCAL_MACHINE\SOFTWARE\139665270\
Parameters
ServiceDll = "%Program Files%\Iefg\Nefghijkl.pic"

It modifies the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
GDIPlus
FontCachePath = "%Application Data%"

(Note: The default value data of the said registry entry is %User Profile%\Local Settings\Application Data.)

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\RemoteAccess\RouterManagers\
Ip
DLLPath = "%System Root%\2468300.dll"

(Note: The default value data of the said registry entry is {random values}.)

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\RemoteAccess\RouterManagers\
Ip
DLLPath = "%System Root%\2737600.dll"

(Note: The default value data of the said registry entry is {random values}.)

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\RemoteAccess\RouterManagers\
Ip
DLLPath = "%System Root%\2768400.dll"

(Note: The default value data of the said registry entry is {random values}.)

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\RemoteAccess\RouterManagers\
Ip
DLLPath = "%System Root%\2287600.dll"

(Note: The default value data of the said registry entry is {random values}.)

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\RemoteAccess\RouterManagers\
Ip
DLLPath = "%System Root%\414000.dll"

(Note: The default value data of the said registry entry is {random values}.)

Dropping Routine

This Trojan drops the following files:

  • %System Root%\2468300.dll
  • %System Root%\WinWall32.gif
  • %System Root%\2737600.dll
  • %System Root%\2768400.dll
  • %System Root%\2287600.dll
  • %System Root%\414000.dll
  • %User Temp%\AppLaunch\App.ine
  • %Program Files%\Iefg\Nefghijkl.pic

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

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
    • 149431839
  • In HKEY_LOCAL_MACHINE\SOFTWARE\149431839
    • Parameters
  • In HKEY_LOCAL_MACHINE\SOFTWARE
    • 108665580
  • In HKEY_LOCAL_MACHINE\SOFTWARE
    • 139665270
  • In HKEY_LOCAL_MACHINE\SOFTWARE
    • 201475763

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
    • FacbookUpdate = "%User Profile%\Application Data\FacbookUpdate.exe"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\149431839\Parameters
    • ServiceDll = "%Program Files%\Iefg\Nefghijkl.pic"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\108665580
    • imgsvc = "StiSvc,Defghi Klmnopqr Tuv"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\139665270\Parameters
    • ServiceDll = "%Program Files%\Iefg\Nefghijkl.pic"

Step 5

Restore these modified registry values

[ Learn More ]

Important:Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this only if you know how to or you can seek your system administrator's help. You may also check out this Microsoft article first before modifying your computer's registry.

  • In HKEY_CURRENT_USER\Software\Microsoft\GDIPlus
    • From: FontCachePath = "%Application Data%"
      To: FontCachePath = ""%User Profile%\Local Settings\Application Data""
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\RemoteAccess\RouterManagers\Ip
    • From: DLLPath = "%System Root%\2468300.dll"
      To: DLLPath = ""{random values}""
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\RemoteAccess\RouterManagers\Ip
    • From: DLLPath = "%System Root%\2737600.dll"
      To: DLLPath = ""{random values}""
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\RemoteAccess\RouterManagers\Ip
    • From: DLLPath = "%System Root%\2768400.dll"
      To: DLLPath = ""{random values}""
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\RemoteAccess\RouterManagers\Ip
    • From: DLLPath = "%System Root%\2287600.dll"
      To: DLLPath = ""{random values}""
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\RemoteAccess\RouterManagers\Ip
    • From: DLLPath = "%System Root%\414000.dll"
      To: DLLPath = ""{random values}""

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.
  • %System Root%\2468300.dll
  • %System Root%\WinWall32.gif
  • %System Root%\2737600.dll
  • %System Root%\2768400.dll
  • %System Root%\2287600.dll
  • %System Root%\414000.dll
  • %User Temp%\AppLaunch\App.ine
  • %Program Files%\Iefg\Nefghijkl.pic

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.
  • %User Temp%\AppLaunch
  • %Program Files%\Iefg

Step 8

Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_INJECT.CWC. 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 deleted/modified files and/or registry entries from backup

*Note: Only Microsoft-related files/keys/values will be restored. If this malware/grayware also deleted registry keys/values related to programs that are not from Microsoft, please reinstall those programs on your computer.

    • %Application Data%\GDIPFONTCACHEV1.DAT

Step 10

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%\syslog.dat
  • %Program Files%\Iefg\Nefghijkl.pic
  • %System Root%\system32.txt
  • %User Temp%\AppLaunch\Service.exe


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