Analysis by: jont
 PLATFORM:

Windows 2000, XP, Server 2003

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  TECHNICAL DETAILS

File Size: 15,126,528 bytes
File Type: PE
Memory Resident: No
Initial Samples Received Date: 07 Dec 2010

Installation

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

  • %Windows%\Winece.exe

(Note: %Windows% is the Windows folder, which is usually C:\Windows or C:\WINNT.)

Autostart Technique

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
MicrosoftOfficeTools = "%Windows%\Winece.exe"

Other System Modifications

This Trojan modifies the following registry entries:

HKEY_CURRENT_USER\Control Panel\Desktop
Wallpaper = NTLDR.sys

(Note: The default value data of the said registry entry is {Path and file name of image set as wallpaper}.)

  SOLUTION

Minimum Scan Engine: 8.900
VSAPI PATTERN File: 7.684.03
VSAPI PATTERN Date: 07 Dec 2010
VSAPI PATTERN Date: 12/7/2010 12:00:00 AM

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

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\Run
    • MicrosoftOfficeTools = %Windows%\Winece.exe

Step 3

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_CURRENT_USER\Control Panel\Desktop
    • From: Wallpaper = NTLDR.sys
      To: Wallpaper = {Path and file name of image set as wallpaper}

Step 4

Scan your computer with your Trend Micro product to delete files detected as TROJ_DOCSCAR.A. 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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