BKDR_HUPIGON.EVT

 Modified by: Marvelous Pelin

 ALIASES:

Trojan:Win32/Agent (Microsoft); Trojan.Delf.Agent.AC (BitDefender); Trojan.JS.StartPage.bo (Kaspersky)

 PLATFORM:

Windows

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

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

Infection Channel:

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.

  TECHNICAL DETAILS

File Size:

119,296 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

10 Jun 2015

Payload:

Connects to URLs/IPs

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 the following files:

  • %Program FIles%\Internet Explorer\MUI\iexplore.exe
  • %System%\reg1_{random numbers}.reg - adds registry entries
  • %System%\reg2_{random numbers}.reg - adds registry entries
  • %Program Files%\Common Files\taodwq.ico

(Note: %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.. %Program Files% is the Program Files folder, where it usually is C:\Program Files on all Windows operating system versions; C:\Program Files (x86) for 32-bit applications running on Windows 64-bit operating systems.)

It drops and executes the following files:

  • %System%\{random filename}.vbs - executes other component files
  • %Program Files%\Common Files\{random filename}.jse - executes other component files and send keyboard commands to certain windows.

(Note: %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.. %Program Files% is the Program Files folder, where it usually is C:\Program Files on all Windows operating system versions; C:\Program Files (x86) for 32-bit applications running on Windows 64-bit operating systems.)

It adds the following processes:

  • iexplore.exe

Other System Modifications

This backdoor adds the following registry keys:

HKEY_CLASSES_ROOT\.gke
{Default} = gkefile

HKEY_CLASSES_ROOT\gkefile
{Default} = {random values}

It adds the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
HideDesktopIcons\NewStartPanel
{random values} = 1

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
HideDesktopIcons\ClassicStartMenu
{random values} = 1

HKEY_CLASSES_ROOT\gkefile\shell\
open\command
{Default} = WScript.exe "%Program Files%\Common Files\{name of this jse file}""%1"

HKEY_CLASSES_ROOT\CLSID\{random values}\
shell\{random values}\Command
{Default} = %Program Files%\Internet Explorer\MUI\iexplore.exe %1 http://d1.kkxp.cn

HKEY_CLASSES_ROOT\CLSID\{random values}\
shell\{random values}\Command
{Default} = Rundll32.exe Shell32.dll, Control_RunDLL Inetcpl.cpl

HKEY_CLASSES_ROOT\CLSID\{random values}\
ShellFolder
{Default} = HideOnDesktopPerUser

HKEY_CLASSES_ROOT\CLSID\{random values}\
ShellFolder
Attributes = 0

HKEY_CLASSES_ROOT\gkefile
IsShortcut =

HKEY_CLASSES_ROOT\gkefile
NeverShowExt =

It modifies the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
Hidden = 2

(Note: The default value data of the said registry entry is 1.)

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
Explorer
NoInternetIcon = 1

(Note: The default value data of the said registry entry is 0.)

Other Details

This backdoor connects to the following possibly malicious URL:

  • http://www.{BLOCKED}a.net
  • http://www.{BLOCKED}6.com
  • http://d1.{BLOCKED}p.cn/error.html

It does the following:

  • The malware deletes LNK files in %All Users Profile%\Desktop and replace them with GKE files with the same filename.
  • The malware deletes LNK files %All Users Profile%\Start Menu\Programs and replace them with GKE files with the same filename.
  • Executes Microsoft.vbs and flash.scf then sends keyboard commands to the executed files.

(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.)

  SOLUTION

Minimum Scan Engine:

9.800

VSAPI OPR PATTERN File:

5.883.00

VSAPI OPR PATTERN Date:

08 Apr 2009

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_CLASSES_ROOT\.gke
    • {Default} = gkefile
  • In HKEY_CLASSES_ROOT\gkefile
    • {Default} = {random values}

Step 5

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_CLASSES_ROOT\CLSID\{random values}\DefaultIcon
    • {Default} = %Program FIles%\Internet Explorer\iexplore.exe
  • In HKEY_CLASSES_ROOT\CLSID\{random values}\shell\{random values}\Command
    • {Default} = %Program Files%\Internet Explorer\MUI\iexplore.exe %1 http://d1.kkxp.cn
  • In HKEY_CLASSES_ROOT\CLSID\{random values}\shell\{random values}\Command
    • {Default} = Rundll32.exe Shell32.dll, Control_RunDLL Inetcpl.cpl
  • In HKEY_CLASSES_ROOT\CLSID\{random values}\ShellFolder
    • {Default} = HideOnDesktopPerUser
  • In HKEY_CLASSES_ROOT\CLSID\{random values}\ShellFolder
    • Attributes = 0
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\HideDesktopIcons\NewStartPanel
    • {random values} = 1
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\HideDesktopIcons\ClassicStartMenu
    • {random values} = 1

Step 6

Restore this modified 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\Policies\Explorer
    • From: NoInternetIcon = 1
      To: NoInternetIcon = 0
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
    • From: Hidden = 2
      To: Hidden = 1

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.
  • %Program Files%\Common Files\{random filename}.jse
  • %System%\{random filename}.vbs
  • %System%\reg1_{random numbers}.reg
  • %System%\reg2_{random numbers}.reg
  • %Program Files%\Common Files\taodwq.ico
  • %Program FIles%\Internet Explorer\MUI\iexplore.exe
  • %All Users Profile%\Desktop\{filename of deleted LNK file}.gke
  • %All Users Profile%\Start Menu\Programs\{filename of deleted LNK file}.gke

Step 8

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