Analysis by: Christopher Daniel So
 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel: Downloaded from the Internet, Dropped by other malware

This backdoor may be downloaded by other malware/grayware from remote sites.

It executes then deletes itself afterward.

It connects to a website to send and receive information.

  TECHNICAL DETAILS

File Size: Varies
File Type: EXE, DLL
Memory Resident: Yes
Initial Samples Received Date: 17 Sep 2012
Payload: Connects to URLs/IPs

Arrival Details

This backdoor may be downloaded by the following malware/grayware from remote sites:

It may be downloaded from the following remote sites:

  • http://{BLOCKED}.{BLOCKED}.104.149/public/help/111.exe

Installation

This backdoor drops and executes the following files:

  • %System%\mspmsnsv.dll - also detected by Trend Micro as BKDR_POISON.BMN

(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 drops the following copies of itself into the affected system:

  • %User Temp%\{random number}.dat

(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.)

Its DLL component is injected to the following process(es):

  • SVCHOST.EXE

It executes then deletes itself afterward.

Other System Modifications

This backdoor deletes the following files:

  • %System%\mspmsnsv.dll - a legitimate Windows file

(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.)

Backdoor Routine

This backdoor connects to the following websites to send and receive information:

  • ie.{BLOCKED}1.co.uk

  SOLUTION

Minimum Scan Engine: 9.200
FIRST VSAPI PATTERN FILE: 9.402.03
FIRST VSAPI PATTERN DATE: 18 Sep 2012
VSAPI OPR PATTERN File: 9.403.00
VSAPI OPR PATTERN Date: 18 Sep 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 BKDR_POISON.BMN

Step 3

Scan your computer with your Trend Micro product and note files detected as BKDR_POISON.BMN

Step 4

Restart in Safe Mode

[ Learn More ]

Step 5

Search and delete the file detected as BKDR_POISON.BMN

[ Learn More ]
Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden files in the search result.

Step 6

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

Step 7

Restore this file from backup only Microsoft-related files will be restored. If this malware/grayware also deleted files related to programs that are not from Microsoft, please reinstall those programs on you computer again.

  • %System%\mspmsnsv.dll


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