BKDR_PLUGX.HEL


 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:

Dropped by other malware, Downloaded from the Internet

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 does not have any propagation routine.

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

It does not have any downloading capability.

It deletes the initially executed copy of itself.

  TECHNICAL DETAILS

File Size:

155,648 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

25 Jul 2014

Payload:

Drops files, Terminates processes, Compromises system security,

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.

Installation

This backdoor drops a copy of itself in the following folders using different file names:

  • %Application Data%\fgjsdft.exe (For Windows Vista and above only)
  • %Windows%\fgjsdft.exe (For Windows Vista below only)

(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Roaming on Windows Vista and 7.. %Windows% is the Windows folder, which is usually C:\Windows.)

It creates the following folders:

  • %All Users Profile%\DRM\xs

(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.)

It adds the following mutexes to ensure that only one of its copies runs at any one time:

  • Global\{random}

Autostart Technique

This backdoor adds the following registry entries to enable its automatic execution at every system startup:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
fgjsdft = "%Windows%\fgjsdft.exe" (For Windows Vista below only)

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
fgjsdft = "%Application Data%\fgjsdft.exe" (For Windows Vista and above only)

Other System Modifications

This backdoor adds the following registry keys:

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

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

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

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

Propagation

This backdoor does not have any propagation routine.

Backdoor Routine

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

  • Copy, move, rename, delete files
  • Create directories
  • Create files
  • Enumerate files
  • Execute files
  • Get drive information
  • Get file information
  • Open and modify files
  • Log keystrokes and active window
  • Enumerate TCP and UDP connections
  • Enumerate network resources
  • Set TCP connection state
  • Lock workstation
  • Log off user
  • Restart/Reboot/Shutdown system
  • Display a message box
  • Perfrom port mapping
  • Enumerate processes
  • Get process information
  • Terminate processes
  • Enumerate registry keys
  • Create registry keys
  • Delete registry keys
  • Copy registry keys
  • Enumerate registry entries
  • Modify registry entries
  • Delete registry values
  • Screen capture
  • Delete services
  • Enumerate services
  • Get service information
  • Modify services
  • Start services
  • Perform remote shell
  • Host Telnet server
  • Connect to a database server and execute SQL statement

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

  • http://{BLOCKED}uy.{BLOCKED}dler.com:53/{random generated value}
  • http://{BLOCKED}uy.{BLOCKED}dler.com:8080/{random generated value}

Dropping Routine

This backdoor drops the following files:

  • %All Users Profile%\DRM\xs\{random characters}

(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.)

Download Routine

This backdoor does not have any downloading capability.

Other Details

This backdoor deletes the initially executed copy of itself

NOTES:

It does not have rootkit capabilities.

It does not exploit any vulnerability.

  SOLUTION

Minimum Scan Engine:

9.700

VSAPI OPR PATTERN File:

10.953.00

VSAPI OPR PATTERN Date:

30 Jul 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

Restart in Safe Mode

[ Learn More ]

Step 4

Delete this registry value

[ 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_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • fgjsdft = "%Windows%\fgjsdft.exe" (For Windows Vista below only)
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • fgjsdft = "%Application Data%\fgjsdft.exe" (For Windows Vista and above only)

Step 5

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_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Setttings\5.0
    • User Agent
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Setttings
    • User Agent

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.
  • %All Users Profile%\DRM\xs

Step 7

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