Analysis by: Cris Nowell Pantanilla

 PLATFORM:

Windows

 OVERALL RISK RATING:
 REPORTED INFECTION:

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

This Trojan arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites. It may be manually installed by a user.

  TECHNICAL DETAILS

File Size: 1,232,896 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 04 Aug 2017

Arrival Details

This Trojan arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

It may be manually installed by a user.

Installation

This Trojan drops the following files:

  • %Program Files%\Notepad2CN\License.txt
  • %Program Files%\Notepad2CN\Notepad2.ini
  • %Program Files%\Notepad2CN\Notepad2.txt
  • %Program Files%\Notepad2CN\Notepad2CN.exe
  • %Program Files%\Notepad2CN\skins.db
  • %Program Files%\Notepad2CN\uninst.exe
  • %Program Files%\Notepad2CN\upsoar.ini
  • %Start Menu%\Programs\ÔƼÇÊ ±¾
  • %Start Menu%\Programs\ÔƼÇÊ ±¾\жÔØ.lnk
  • %Start Menu%\Programs\ÔƼÇÊ ±¾\ÔƼÇÊ ±¾.lnk
  • %Desktop%\ÔƼÇÊ ±¾.lnk
  • {malware path}\net.dat ← encrypted binary
  • {malware path}\setup.dat ← installer for Notepad2CN
  • {malware path}\upsoar.ini ← configuration file

(Note: %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.. %Start Menu% is the Start Menu folder, where it usually is C:\Documents and Settings\{user name}\Start Menu on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming\Microsoft\Windows\Start Menu 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.. %Desktop% is the desktop folder, where it usually is C:\Documents and Settings\{user name}\Desktop in Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\Desktop in 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:

  • %Program Files%\Notepad2CN

(Note: %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 Details

This Trojan connects to the following possibly malicious URL:

  • http://www.{BLOCKED}uazi.com/0/sts.html
  • http://www.{BLOCKED}hyk.com/1.dll
  • http://www.{BLOCKED}jhf.com/1.dll

It does the following:

  • When executed, it will act as a installer for "Notepad2" (a normal text editor). However, using the "-silent" parameter, the file will also drop and execute a malicious binary into the system.

  SOLUTION

Minimum Scan Engine: 9.850
FIRST VSAPI PATTERN FILE: 13.574.04
FIRST VSAPI PATTERN DATE: 04 Aug 2017
VSAPI OPR PATTERN File: 13.575.00
VSAPI OPR PATTERN Date: 05 Aug 2017

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

Identify and terminate files detected as TROJ_KUZZLE.A

[ Learn More ]
  1. Windows Task Manager may not display all running processes. In this case, please use a third-party process viewer, preferably Process Explorer, to terminate the malware/grayware/spyware file. You may download the said tool here.
  2. If the detected file is displayed in either Windows Task Manager or Process Explorer but you cannot delete it, restart your computer in safe mode. To do this, refer to this link for the complete steps.
  3. If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.

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. %Program Files%\Notepad2CN

Step 4

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%\Notepad2CN\License.txt

%Program Files%\Notepad2CN\Notepad2.ini

%Program Files%\Notepad2CN\Notepad2.txt

%Program Files%\Notepad2CN\Notepad2CN.exe

%Program Files%\Notepad2CN\skins.db

%Program Files%\Notepad2CN\uninst.exe

%Program Files%\Notepad2CN\upsoar.ini

%Start Menu%\Programs\ÔƼÇʱ¾

%Start Menu%\Programs\ÔƼÇʱ¾\жÔØ.lnk

%Start Menu%\Programs\ÔƼÇʱ¾\ÔƼÇʱ¾.lnk

%Desktop%\ÔƼÇʱ¾.lnk

{malware path}\net.dat

{malware path}\setup.dat

{malware path}\upsoar.ini


Step 5

Scan your computer with your Trend Micro product to delete files detected as TROJ_KUZZLE.A. 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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