Analysis by: Adrian Cofreros

 PLATFORM:

Windows

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

Infection Channel: Dropped by other malware

This Trojan may be dropped by other malware.

It does not have any propagation routine.

It does not have any backdoor routine.

It accesses websites to download files. This action allows this malware to possibly add other malware on the affected computer.

It does not have any information-stealing capability.

It deletes itself after execution.

  TECHNICAL DETAILS

File Size: 10,240 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 26 Dec 2014
Payload: Downloads files

Arrival Details

This Trojan may be dropped by the following malware:

  • TROJ_DROPTER.HNY

Installation

This Trojan drops and executes the following files:

  • %User Profile%\Applications\Microsoft\msviewer.exe - modified copy of itself, dropped when user is not administrator, detected as TROJ_DLOADE.SMC2
  • %Program Files%\Windows NT\Accessories\Microsoft\msviewer.exe - modified copy of itself, dropped when user is administrator, detected as TROJ_DLOADE.SMC2

(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.. %Program Files% is the Program Files folder, where it usually is C:\Program Files on all Windows operating system versions; C:\Program Files (x86) for 32-bit applications running on Windows 64-bit operating systems.)

It creates the following folders:

  • %Program Files%\Windows NT\Accessories\Microsoft
  • %User Profile%\Applications\Microsoft

(Note: %Program Files% is the Program Files folder, where it usually is C:\Program Files on all Windows operating system versions; C:\Program Files (x86) for 32-bit applications running on Windows 64-bit operating systems.. %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.)

Autostart Technique

This Trojan drops the following file(s) in the Windows User Startup folder to enable its automatic execution at every system startup:

  • %User Startup%\Windows Message.lnk (Versions lower than Windows Vista)- shortcut to its modified drop copy
  • %Start Menu%\Programs\Startup\Windows Message.lnk (Windows Vista and higher versions) -shortcut to its modified drop copy

(Note: %User Startup% is the current user's Startup folder, which is usually C:\Windows\Profiles\{user name}\Start Menu\Programs\Startup on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Start Menu\Programs\Startup on Windows NT, and C:\Documents and Settings\{User name}\Start Menu\Programs\Startup.. %Start Menu% is the Start Menu folder, where it usually is C:\Documents and Settings\{user name}\Start Menu on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming\Microsoft\Windows\Start Menu on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.)

Propagation

This Trojan does not have any propagation routine.

Backdoor Routine

This Trojan does not have any backdoor routine.

Download Routine

This Trojan accesses websites to download the following files:

  • http://{BLOCKED}g.twinkes.net/otete2/css/topblack.php

It saves the files it downloads using the following names:

  • %User Temp%\msupdata.exe - it will be executed
  • %User Temp%\{random}.tmp – this will be created if unable to create 'msupdata.exe', it will be executed

(Note: %User Temp% is the user's temporary folder, where it usually is C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local\Temp on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.)

Information Theft

This Trojan does not have any information-stealing capability.

Other Details

This Trojan deletes itself after execution.

NOTES:

It does not have rootkit capabilities.

It does not exploit any vulnerability.

  SOLUTION

Minimum Scan Engine: 9.700
FIRST VSAPI PATTERN FILE: 11.370.03
FIRST VSAPI PATTERN DATE: 26 Dec 2014
VSAPI OPR PATTERN File: 11.371.00
VSAPI OPR PATTERN Date: 27 Dec 2014

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

Note that not all files, folders, and registry keys and entries are installed on your computer during this malware's/spyware's/grayware's execution. This may be due to incomplete installation or other operating system conditions. If you do not find the same files/folders/registry information, please proceed to the next step.

Step 3

Remove malware/grayware files that dropped/downloaded TROJ_DLOADE.BFC. (Note: Please skip this step if the threats listed below have already been removed.)

    • TROJ_DROPTER.HNY

Step 4

Remove malware/grayware files dropped/downloaded by TROJ_DLOADE.BFC. (Note: Please skip this step if the threats listed below have already been removed.)

    • TROJ_DLOADE.SMC2

Step 5

Identify and terminate files detected as TROJ_DLOADE.BFC

[ Learn More ]
  1. 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 6

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.
  • %Program Files%\Windows NT\Accessories\Microsoft
  • %User Profile%\Applications\Microsoft

Step 7

Search and delete this file

[ Learn More ]
There may be some 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 Startup%\Windows Message.lnk (Versions lower than Windows Vista)- shortcut to its modified drop copy
  • %Start Menu%\Programs\Startup\Windows Message.lnk (Windows Vista and higher versions) -shortcut to its modified drop copy
  • %User Temp%\msupdata.exe
  • %User Temp%\{random}.tmp

Step 8

Scan your computer with your Trend Micro product to delete files detected as TROJ_DLOADE.BFC. 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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