ALIASES:

TrojanDropper:Win32/Dunik!rts (Microsoft); Trojan.ADH (Symantec); Trojan-PSW.Win32.Bjlog.drhp (Kaspersky); Trojan.Win32.Generic!BT (Sunbelt); Trojan horse BackDoor.Hupigon3.AQPA (AVG)

 PLATFORM:

Windows

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

  • 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: 3,213,209 bytes
File Type: EXE
Memory Resident: No
Initial Samples Received Date: 19 Feb 2015

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 creates the following folders:

  • %User Temp%\T130131230116000018330
  • %User Temp%\T130131550928000018434
  • %User Temp%\nst5.tmp
  • %Program Files%\Gadwin Systems
  • %Program Files%\Gadwin Systems\PrintScreen

(Note: %User Temp% is the user's temporary folder, where it usually is C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local\Temp 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.. %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.)

Other System Modifications

This backdoor deletes the following files:

  • %User Temp%\nst5.tmp

(Note: %User Temp% is the user's temporary folder, where it usually is C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local\Temp 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.)

Dropping Routine

This backdoor drops the following files:

  • %User Temp%\t130131230116000018330\{malware file name}.exe
  • %User Temp%\t130131550928000018434\{malware file name}.exe
  • %User Temp%\nst3.tmp
  • %User Temp%\nst5.tmp\LangDLL.dll
  • %User Temp%\nst5.tmp\ioSpecial.ini
  • %User Temp%\nst5.tmp\modern-wizard.bmp
  • %User Temp%\nst5.tmp\InstallOptions.dll
  • %Program Files%\Gadwin Systems\PrintScreen\file_id.diz

(Note: %User Temp% is the user's temporary folder, where it usually is C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local\Temp 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.. %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.)

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine: 9.700

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

Search and delete these components

[ Learn More ]
There may be some components 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.
  • %User Temp%\t130131230116000018330\{malware file name}.exe
  • %User Temp%\t130131550928000018434\{malware file name}.exe
  • %User Temp%\nst3.tmp
  • %User Temp%\nst5.tmp\LangDLL.dll
  • %User Temp%\nst5.tmp\ioSpecial.ini
  • %User Temp%\nst5.tmp\modern-wizard.bmp
  • %User Temp%\nst5.tmp\InstallOptions.dll
  • %Program Files%\Gadwin Systems\PrintScreen\file_id.diz

Step 3

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.
  • %User Temp%\T130131230116000018330
  • %User Temp%\T130131550928000018434
  • %User Temp%\nst5.tmp
  • %Program Files%\Gadwin Systems
  • %Program Files%\Gadwin Systems\PrintScreen

Step 4

Scan your computer with your Trend Micro product to delete files detected as BKDR_HUPIGON.SPZ. 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 5

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.

  • %User Temp%\nst5.tmp


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