Analysis by: Christopher Daniel So
 Modified by: Sabrina Lei Sioting

 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

  OVERVIEW

This Trojan may be dropped by other malware.

  TECHNICAL DETAILS

File Size: 131,584 bytes
File Type: DLL
Initial Samples Received Date: 13 Apr 2011

Arrival Details

This Trojan may be dropped by the following malware:

  • TROJ_DROPPER.KFT

Installation

This Trojan injects itself into the following processes as part of its memory residency routine:

  • explorer.exe
  • svchost.exe
  • ctfmon.exe

Other System Modifications

This Trojan adds the following registry keys:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Enum\Root\LEGACY_WINSVCFS

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\winsvcfs

It adds the following registry entries as part of its installation routine:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Enum\Root\LEGACY_WINSVCFS\
0000
Service = winsvcfs

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\winsvcfs
ImagePath = %SystemRoot%\system32\svchost.exe -k LocalService

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\winsvcfs
DisplayName = winsvcfs

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\winsvcfs\Parameters
ServiceDll = %system root%\Documents and Settings\All Users\Application Data\winsvcfs.DLL

  SOLUTION

Minimum Scan Engine: 8.900

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

Step 1: Identify and note files detected as TROJ_INJECT.UUU by scanning the computer using your Trend Micro product

[ Learn More ]

  1. For Windows 98 and ME users, Windows Task Manager may not display all running processes. In this case, please use a third-party process viewer, preferably Process Explorer, to terminate the malware/grayware/spyware file. You may download the said tool here.
  2. If the detected file is displayed in either Windows Task Manager or Process Explorer but you cannot delete it, restart your computer in safe mode. To do this, refer to this link for the complete steps.
  3. If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.

Step 2: Restart in Safe Mode

[ Learn More ]

• For Windows 2000 users

  1. Restart your computer.
  2. Press the F8 key, when you see the Starting Windows bar at the bottom of the screen.
  3. Choose the Safe Mode option from the Windows Advanced Options Menu then press Enter.

• For Windows XP users

  1. Restart your computer.
  2. Press F8 after the Power-On Self Test (POST) is done. If the Windows Advanced Options Menu does not appear, try restarting and then pressing F8 several times after the POST screen.
  3. Choose the Safe Mode option from the Windows Advanced Options Menu then press Enter.

• For Windows Server 2003 users

  1. Restart your computer.
  2. Press F8 after Windows starts up. If the Windows Advanced Options Menu does not appear, try restarting again and then pressing F8 several times after restarting.
  3. On the Windows Advanced Option menu, use the arrow keys to select Safe Mode, and then press Enter.

Step 3: Search and delete the noted file detected as TROJ_INJECT.UUU

[ Learn More ]

To search and delete the .DLL file:

  1. Right-click on the Start button then choose Search... or Find..., depending on the version of Windows you are running.
  2. In the Named input box, type the name(s) of the file(s) detected earlier.
  3. In the Look In drop-down list, select My Computer, then press Enter.
  4. Once located, select the file then press SHIFT+DELETE.

Step 3

Remove malware files dropped/downloaded by TROJ_INJECT.UUU

     TROJ_DROPPER.KFT

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.

  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Enum\Root\
    • LEGACY_WINSVCFS
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\
    • winsvcfs

Step 5

Scan your computer with your Trend Micro product to delete files detected as TROJ_INJECT.UUU. 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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