Analysis by: Sabrina Lei Sioting

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel: Dropped by other malware

This Trojan may be dropped by other malware.

  TECHNICAL DETAILS

File Size: 489,088 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 30 May 2012
Payload: Steals information

Arrival Details

This Trojan may be dropped by the following malware:

  • TROJ_DROPPER.ZGD

Installation

This Trojan drops the following copies of itself into the affected system:

  • %System%\Windupdt\winupdate.exe

(Note: %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and ME, C:\WINNT\System32 on Windows NT and 2000, or C:\Windows\System32 on Windows XP and Server 2003.)

It creates the following folders:

  • %System%\Windupdt

(Note: %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and ME, C:\WINNT\System32 on Windows NT and 2000, or C:\Windows\System32 on Windows XP and Server 2003.)

It terminates the execution of the copy it initially executed and executes the copy it drops instead.

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
winupdater = "%System%\Windupdt\winupdate.exe"

It modifies the following registry entries to ensure it automatic execution at every system startup:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Winlogon
Userinit = "%System%\userinit.exe,%System%\Windupdt\winupdate.exe"

(Note: The default value data of the said registry entry is %System%\userinit.exe,.)

Other System Modifications

This Trojan adds the following registry keys as part of its installation routine:

HKEY_CURRENT_USER\Software\DC3_FEXEC

Dropping Routine

This Trojan drops the following file(s), which it uses for its keylogging routine:

  • %User Temp%\dclogs.sys

(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.)

Stolen Information

This Trojan sends the gathered information via HTTP POST to the following URL:

  • {BLOCKED}.no-ip.org

NOTES:

This Trojan hooks the following APIs:

  • CloseHandle
  • DeleteFileA
  • ExitProcess
  • FindClose
  • FindFirstFileA
  • GetCurrentDirectoryA
  • GetExitCodeProcess
  • GetTempPathA
  • OpenProcess
  • SetCurrentDirectoryA
  • Sleep
  • WaitForSingleObject

  SOLUTION

Minimum Scan Engine: 9.200
FIRST VSAPI PATTERN FILE: 9.154.05
FIRST VSAPI PATTERN DATE: 31 May 2012
VSAPI OPR PATTERN File: 9.155.00
VSAPI OPR PATTERN Date: 31 May 2012

Step 1

For Windows XP and Windows Server 2003 users, before doing any scans, please make sure you disable System Restore to allow full scanning of your computer.

Step 2

Remove the malware/grayware file that dropped/downloaded TROJ_VBINJECT.XG

Step 3

Identify and delete files detected as TROJ_VBINJECT.XG using either the Startup Disk or Recovery Console

[ Learn More ]

Step 4

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. Before you could do this, you must restart in Safe Mode. For instructions on how to do this, you may refer to this page If the preceding step requires you to restart in safe mode, you may proceed to edit the system registry.

  • In HKEY_CURRENT_USER\Software
    • DC3_FEXEC

Step 5

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
    • winupdater = "%System%\Windupdt\winupdate.exe"

Step 6

Restore this modified 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 NT\CurrentVersion\Winlogon
    • From: Userinit = "%System%\userinit.exe,%System%\Windupdt\winupdate.exe"
      To: Userinit = "%System%\userinit.exe,"

Step 7

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%\Windupdt

Step 8

Search and delete this file

[ Learn More ]
There may be some component files 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%\dclogs.sys

Step 9

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