BKDR_PROXY.MD

September 08, 2014
 Modified by: Jaime Benigno Reyes
 PLATFORM:

Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)

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

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Downloaded from the Internet, Dropped by other malware

This backdoor arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

It executes commands from a remote malicious user, effectively compromising the affected system.

  TECHNICAL DETAILS

File Size:

282,112 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

03 Sep 2014

Payload:

Compromises system security, Collects system information

Arrival Details

This backdoor arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

Autostart Technique

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

  • %All Users Profile%\Microsoft\Windows\Start Menu\Programs\Startup\nvxdsync.lnk (Windows Vista and higher versions)
  • %Common Startup%\nvxdsync.lnk (Versions lower than Windows Vista)

(Note: %All Users Profile% is the All Users or Common profile folder, which is C:\Documents and Settings\All Users in Windows 2000, XP, and Server 2003, and C:\ProgramData in Windows Vista and 7.. %Common Startup% is the system's shared Startup folder, which is usually C:\Documents and Settings\All Users\Start Menu\Programs\Startup on Windows 2000, XP, and Server 2003.)

Backdoor Routine

This backdoor executes the following commands from a remote malicious user:

  • Create processes with user's privilege
  • Create, copy or delete folders and or files
  • Find, read and get file information
  • Get drive information
  • Download and execute arbitrary files
  • Perform remote shell commands

It connects to the following URL(s) to send and receive commands from a remote malicious user:

  • www.{BLOCKED}x.co.jp/{random 5-digit number}.html

Information Theft

This backdoor gathers the following data:

  • computer name

NOTES:

It has the following file information to trick users that it is a legitimate file:

  • File Version: 6.1.7600.16385
  • Description: Machine Debug Manager
  • Copyright: © Microsoft Corporation. All rights reserved.
  • Company: Microsoft Corporation
  • File Version: 6.00.8149
  • Internal Name: mdm.exe
  • Language: English (United States)
  • Original File name: mdm.exe
  • Product Name: Microsoft® Windows® Operating System
  • Product Version: 6.00.8149

It connects to the following non-malicious sites to trick users into thinking it is a legitimate file:

  • www.microsoft.com
  • www.msftncsi.com
  • www.yahoo.co.jp

It will not connect to its C&C server if there are open windows that contain any of the following strings:

  • ollydbg
  • Process Explorer
  • Process Hacker
  • Process Monitor
  • SoftICE
  • W32Dasm
  • Wireshark

It finds a user of the computer that employs a proxy by reading proxy-related registry entries. If it finds one, it employs the user's proxy server settings to connect to its C&C server.

It does not have rootkit capabilities.

It does not exploit any vulnerability.

  SOLUTION

Minimum Scan Engine:

9.700

VSAPI OPR PATTERN File:

11.127.00

VSAPI OPR PATTERN Date:

04 Sep 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

Identify and terminate files detected as BKDR_PROXY.MD

[ 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 4

Search and delete these files

[ 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.  
  • %All Users Profile%\Microsoft\Windows\Start Menu\Programs\Startup\nvxdsync.lnk (Windows Vista and higher versions)
  • %Common Startup%\nvxdsync.lnk (Versions lower than Windows Vista)

Step 5

Scan your computer with your Trend Micro product to delete files detected as BKDR_PROXY.MD. 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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