Analysis by: Nikko Tamana
 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:

  • In the wild: Yes

  OVERVIEW

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.

  TECHNICAL DETAILS

File Size: 237,568 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 11 Oct 2013

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.

Other System Modifications

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

HKEY_CLASSES_ROOT\MJ
CLSID = "{random values}"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
MJ
CLSID = "{random values}"

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

HKEY_CURRENT_USER\Software\Local AppWizard-Generated Applications

HKEY_CURRENT_USER\Software\Local AppWizard-Generated Applications\
PJM

HKEY_CURRENT_USER\Software\Local AppWizard-Generated Applications\
PJM\Recent File List

HKEY_CURRENT_USER\Software\Local AppWizard-Generated Applications\
PJM\Settings

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings\
User Agent

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings\
User Agent\Post Platform

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings\
5.0\User Agent

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings\
5.0\User Agent\Post Platform

HKEY_CLASSES_ROOT\MJ

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
MJ

Other Details

This backdoor connects to the following possibly malicious URL:

  • http://{BLOCKED}.{BLOCKED}.49.154/update?id={hex values}

It drops the following file(s)/component(s):

  • %System Root%\Documents and Settings\All Users\SxS - Other operating system then Windows Vista and up
  • %System Root%\Documents and Settings\All Users\SxS\bug.log - Other operating system then Windows Vista and up
  • %ProgramData%\SxS - For Windows Vista and up
  • %ProgramData%\SxS\bug.log - For Windows Vista and up
  • %System Root%\Users\All Users\SxS - For Windows Vista and up
  • %System Root%\Users\All Users\SxS\bug.log - For Windows Vista and up

(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.. %ProgramData% is a version of the Program Files folder where any user on a multi-user computer can make changes to programs. This is usually C:\ProgramData in Windows Vista and 7, or C:\Program Files on Windows 2000, XP (32-bit), and Server 2003, or C:\Program Files (x86) on Windows XP (64-bit).)

  SOLUTION

Minimum Scan Engine: 9.300
FIRST VSAPI PATTERN FILE: 10.334.03
FIRST VSAPI PATTERN DATE: 11 Oct 2013
VSAPI OPR PATTERN File: 10.335.00
VSAPI OPR PATTERN Date: 12 Oct 2013

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

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

Step 3

Restart in Safe Mode

[ Learn More ]

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. Before you could do this, you must restart in Safe Mode. For instructions on how to do this, you may refer to this page If the preceding step requires you to restart in safe mode, you may proceed to edit the system registry.

  • In HKEY_CURRENT_USER\Software
    • Local AppWizard-Generated Applications
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings
    • User Agent
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\5.0
    • User Agent
  • In HKEY_CLASSES_ROOT
    • MJ
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes
    • MJ

Step 5

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.
  • %System Root%\Documents and Settings\All Users\SxS - Other operating system then Windows Vista and up
  • %System Root%\Documents and Settings\All Users\SxS\bug.log - Other operating system then Windows Vista and up
  • %ProgramData%\SxS - For Windows Vista and up
  • %ProgramData%\SxS\bug.log - For Windows Vista and up
  • %System Root%\Users\All Users\SxS - For Windows Vista and up
  • %System Root%\Users\All Users\SxS\bug.log - For Windows Vista and up

Step 6

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