Analysis by: Homer Pacag
 PLATFORM:

Windows

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

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

This backdoor may arrive bundled with malware packages as a malware component.

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

  TECHNICAL DETAILS

File Size: 439,042 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 17 Jun 2015
Payload: Collects system information, Steals information

Arrival Details

This backdoor may arrive bundled with malware packages as a malware component.

Installation

This backdoor drops the following component file(s):

  • %All Users Profile%\Human Interface\iusb3mon.exe - non-malicious file used to load BKDR_PLUGX.JA
  • %All Users Profile%\Human Interface\iusb3mon.dll detected as TROJ_PLUGX.JA
  • %All Users Profile%\Human Interface\iusb3mon.exe.mui

(Note: %All Users Profile% is the All Users folder, where it usually is C:\Documents and Settings\All Users on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\ProgramData 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.)

It creates the following folders:

  • %All Users Profile%\Human Interface

(Note: %All Users Profile% is the All Users folder, where it usually is C:\Documents and Settings\All Users on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\ProgramData 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.)

It is injected into the following processes running in memory:

  • svchost.exe
  • msiexec.exe

Autostart Technique

This backdoor registers itself as a system service to ensure its automatic execution at every system startup by adding the following registry entries:

HKLM\SYSTEM\ControlSet001\
Services\Human Interface
ImagePath = %All Users Profile%\Human Interface\iusb3mon.exe

HKLM\SYSTEM\ControlSet001\
Services\Human Interface
DisplayName = Human Interface

HKLM\SYSTEM\ControlSet001\
Services\Human Interface
ObjectName = LocalSystem

HKLM\SYSTEM\ControlSet001\
Services\Human Interface
Description = Human Interface

HKLM\SYSTEM\ControlSet001\
Enum\Root\LEGACY_HUMAN_INTERFACE\
0000
Service = Human Interface

HKLM\SYSTEM\ControlSet001\
Enum\Root\LEGACY_HUMAN_INTERFACE\
0000
DeviceDesc = Human Interface

It registers as a system service to ensure its automatic execution at every system startup by adding the following registry keys:

HKLM\SYSTEM\ControlSet001\
Services\Human Interface

HKLM\SYSTEM\ControlSet001\
Enum\Root\LEGACY_HUMAN_INTERFACE

Backdoor Routine

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

  • Manage files, registries, services and directories
  • Log keystrokes and active window
  • Restart/Reboot/Shutdown system
  • Enumerate processes
  • Terminate processes
  • Get drive information
  • Enumerate network resources
  • Set TCP connection state
  • Lock workstation
  • Display a message box
  • Perfrom port mapping
  • Capture screen
  • Perform remote shell

Other Details

This backdoor drops the following file(s)/component(s):

  • %System Root%\log\haha.txt - contains activity logs of the malware

(Note: %System Root% is the Windows root folder, where it usually is C:\ on all Windows operating system versions.)

NOTES:

It connects to the following URL to send and receive information:

  • ssl.{BLOCKED}ed-clouder.com
  • dns.{BLOCKED}ed-clouder.com

  SOLUTION

Minimum Scan Engine: 9.750
FIRST VSAPI PATTERN FILE: 11.736.07
FIRST VSAPI PATTERN DATE: 17 Jun 2015
VSAPI OPR PATTERN File: 11.737.00
VSAPI OPR PATTERN Date: 17 Jun 2015

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

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.

 
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Enum\Root
    • LEGACY_HUMAN_INTERFACE
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services
    • Human Interface

Step 5

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.
  • %All Users Profile%\Human Interface

Step 6

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

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. DATA_GENERIC
  • In the Look In drop-down list, select My Computer then press Enter.
  • Once located, select the file then press SHIFT+DELETE to delete it.
    *Note: The file name input box title varies depending on the Windows version (e.g. Search for files or folders named or All or part of the file name.).

    • • For Windows Vista, Windows 7, Windows Server 2008, Windows 8, Windows 8.1, and Windows Server 2012:

    1. Open a Windows Explorer window.
      • For Windows Vista, 7, and Server 2008 users, click Start>Computer.
      • For Windows 8, 8.1, and Server 2012 users, right-click on the lower left corner of the screen, then click File Explorer.
    2. In the Search Computer/This PC input box, type:
      DATA_GENERIC
    3. Once located, select the file then press SHIFT+DELETE to delete it.
      *Note: Read the following Microsoft page if these steps do not work on Windows 7.

    Step 8

    Scan your computer with your Trend Micro product to delete files detected as BKDR_PLUGX.JA. 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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