Analysis by: Emilio Marcel Garcia
ALIASES:

Win32:Malware-gen (AVAST)

 PLATFORM:

Windows

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted:

  • 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.

  TECHNICAL DETAILS

File Size: 461,824 bytes
File Type: EXE
Initial Samples Received Date: 24 Feb 2020

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.

Installation

This Trojan drops the following files:

  • %User Temp%\{random characters}.tmp\ioSpecial.ini
  • %User Temp%\{random characters}.tmp\modern-wizard.bmp
  • %User Temp%\{random characters}.tmp\modern-header.bmp
  • %User Temp%\{random characters}.tmp\BrandingURL.dll
  • %User Temp%\{random characters}.tmp\InstallOptions.dll
  • %Program Files%\MuziSoft\Muzi Toolbox\sys15\CadTab.arx
  • %Program Files%\MuziSoft\Muzi Toolbox\sys16\CadTab.arx
  • %Program Files%\MuziSoft\Muzi Toolbox\sys17\CadTab.arx
  • %Program Files%\MuziSoft\Muzi Toolbox\sys18\CadTab.arx
  • %Program Files%\MuziSoft\Muzi Toolbox\Setup.exe
  • %Program Files%\MuziSoft\Muzi Toolbox\uninst.exe
  • %Desktop%\ľ×Ó¹¤¾ßÏä.lnk

(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Local\Temp on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).. %Program Files% is the default Program Files folder, usually C:\Program Files in Windows 2000(32-bit), Server 2003(32-bit), XP, Vista(64-bit), 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit) , or C:\Program Files (x86) in Windows XP(64-bit), Vista(64-bit), 7(64-bit), 8(64-bit), 8.1(64-bit), 2008(64-bit), 2012(64-bit) and 10(64-bit).. %Desktop% is the current user's desktop, which is usually C:\Documents and Settings\{User Name}\Desktop on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\Desktop on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)

It adds the following processes:

  • %Program Files%\MuziSoft\Muzi Toolbox\Setup.exe

(Note: %Program Files% is the default Program Files folder, usually C:\Program Files in Windows 2000(32-bit), Server 2003(32-bit), XP, Vista(64-bit), 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit) , or C:\Program Files (x86) in Windows XP(64-bit), Vista(64-bit), 7(64-bit), 8(64-bit), 8.1(64-bit), 2008(64-bit), 2012(64-bit) and 10(64-bit).)

It creates the following folders:

  • %User Temp%\{random characters}.tmp
  • %Program Files%\MuziSoft

(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Local\Temp on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).. %Program Files% is the default Program Files folder, usually C:\Program Files in Windows 2000(32-bit), Server 2003(32-bit), XP, Vista(64-bit), 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit) , or C:\Program Files (x86) in Windows XP(64-bit), Vista(64-bit), 7(64-bit), 8(64-bit), 8.1(64-bit), 2008(64-bit), 2012(64-bit) and 10(64-bit).)

Other System Modifications

This Trojan deletes the following files:

  • %User Temp%\{random characters}.tmp\ioSpecial.ini
  • %User Temp%\{random characters}.tmp\modern-wizard.bmp
  • %User Temp%\{random characters}.tmp\modern-header.bmp
  • %User Temp%\{random characters}.tmp\BrandingURL.dll
  • %User Temp%\{random characters}.tmp\InstallOptions.dll

(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Local\Temp on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)

It deletes the following folders:

  • %User Temp%\{random characters}.tmp

(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Local\Temp on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)

It adds the following registry entries as part of its installation routine:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\App Paths\
CadTab.arx
(Default) = %Program Files%\MuziSoft\Muzi Toolbox\CadTab.arx

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\App Paths\
CadTab.arx
Path = %Program Files%\MuziSoft\Muzi Toolbox

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
Muzi Toolbox
DisplayName = ľ×Ó¹¤¾ßÏä 1.0.0.8 Build 090505

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
Muzi Toolbox
UninstallString = %Program Files%\MuziSoft\Muzi Toolbox\uninst.exe

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
Muzi Toolbox
DisplayIcon = %Program Files%\MuziSoft\Muzi Toolbox\Setup.exe

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
Muzi Toolbox
DisplayVersion = 1.0.0.8

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
Muzi Toolbox
URLUpdateInfo = http://www.{BLOCKED}g.com/muzi

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
Muzi Toolbox
URLInfoAbout = http://www.{BLOCKED}g.com/muzi

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
Muzi Toolbox
InstallLocation = %Program Files%\MuziSoft\Muzi Toolbox

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
Muzi Toolbox
InstallSource = {Location of original file}

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
Muzi Toolbox
Publisher = Muzi Software

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
Muzi Toolbox
NoModifiy = 1

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
Muzi Toolbox
NoRepair = 1

  SOLUTION

Minimum Scan Engine: 9.850
FIRST VSAPI PATTERN FILE: 15.710.02
FIRST VSAPI PATTERN DATE: 27 Feb 2020
VSAPI OPR PATTERN File: 15.711.00
VSAPI OPR PATTERN Date: 28 Feb 2020

Step 1

Before doing any scans, Windows 7, Windows 8, Windows 8.1, and Windows 10 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 only if you know how to or you can seek your system administrator’s help. You may also check out this Microsoft article first before modifying your computer's registry.

  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\App Paths
    • CadTab.arx
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall
    • Muzi Toolbox

Step 5

Search and delete these files

[ 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%\MuziSoft\Muzi Toolbox\sys15\CadTab.arx
  • %Program Files%\MuziSoft\Muzi Toolbox\sys16\CadTab.arx
  • %Program Files%\MuziSoft\Muzi Toolbox\sys17\CadTab.arx
  • %Program Files%\MuziSoft\Muzi Toolbox\sys18\CadTab.arx
  • %Program Files%\MuziSoft\Muzi Toolbox\Setup.exe
  • %Program Files%\MuziSoft\Muzi Toolbox\uninst.exe
  • %Desktop%\ľ×Ó¹¤¾ßÏä.lnk

Step 6

Restart in normal mode and scan your computer with your Trend Micro product for files detected as Trojan.Win32.STARTPA.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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