Modified by: Clive Fuentebella
ALIASES:

Adware/Agent (FORTINET); a variant of Win32/CnsMin.AD potentially unwanted application (NOD32)

 PLATFORM:

Windows

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

  • Threat Type: Adware

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

This Adware 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: 151,552 bytes
File Type: DLL
Memory Resident: Yes
Initial Samples Received Date: 06 Feb 2020

Arrival Details

This Adware 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 Adware drops the following files:

  • {Malware file path}\jword.ico
  • {Malware file path}\jwordhot.ico
  • %Common Programs%\Japanese keywords\Japanese Keyword Setting.url
  • %Common Programs%\Japanese keywords\About Japanese Keyword.url
  • %Common Programs%\Japanese keywords\Uninstall.lnk

(Note: %Common Programs% is the folder that contains common program groups for all users, which is usually C:\Documents and Settings\All Users\Start Menu\Programs on Windows 2000, XP, and Server 2003, or C:\ProgramData\Microsoft\Windows\Start Menu\Programs on Windows Vista, 7, and 8.)

Autostart Technique

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
CnsMin = Rundll32.exe {Malware file path and name},Rundll32

Other System Modifications

This Adware adds the following registry entries:

HKEY_CURRENT_USER\Software\{Random number}\
CnsMin
Message = 1

HKEY_CURRENT_USER\Software\{Random number}\
CnsMin
LastActive = {Random numbers}

HKEY_CURRENT_USER\Software\{Random number}\
CnsMin
AddProgram = 1

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Main
CNSReset = {Random numbers}

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Main
CNSEnable = 1

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Main
CNSHint = 1

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Main
CNSList = 1

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Main
CNSMenu = {Random numbers}

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Main
CNSAutoUpdate = 1

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Main
Use Custom Search URL = 0

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Internet Explorer\Search
CustomizeSearch = http://search.{BLOCKED}d.jp/jwd_sb_srchcust.htm?ielang={Random characters}

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Internet Explorer\Search
SearchAssistant = http://search.{BLOCKED}d.jp/jwd_sb_srchasst.htm?ielang={Random characters}

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Internet Explorer\Extensions\{Random characters}
CLSID = {Random characters}

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Internet Explorer\Extensions\{Random characters}
ButtonText = Japanese Keywords Homepage

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Internet Explorer\Extensions\{Random characters}
HotIcon = {Malware file path}\jwordhot.ico

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Internet Explorer\Extensions\{Random characters}
Icon = {Malware file path}\jword.ico

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Internet Explorer\Extensions\{Random characters}
DefaultVisible = yes

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Internet Explorer\Extensions\{Random characters}
Exec = http://www.{BLOCKED}d.jp/intro/?partner=AP&type=lk&frm=iebutton

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Internet Explorer\AdvancedOptions\!CNS
Type = group

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Internet Explorer\AdvancedOptions\!CNS
Text = Japanese keywords

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Internet Explorer\AdvancedOptions\!CNS
PlugUIText = @{Malware file path and name},-117

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Internet Explorer\AdvancedOptions\!CNS
Bitmap = {Malware file path and name},1000

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Internet Explorer\AdvancedOptions\!CNS\
Enable
Type = checkbox

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Internet Explorer\AdvancedOptions\!CNS\
Enable
HKeyRoot = {Random number}

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Internet Explorer\AdvancedOptions\!CNS\
Enable
RegPath = SOFTWARE\Microsoft\Internet Explorer\Main

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Internet Explorer\AdvancedOptions\!CNS\
Enable
ValueName = CNSEnable

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Internet Explorer\AdvancedOptions\!CNS\
Enable
DefaultValue = 1

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Internet Explorer\AdvancedOptions\!CNS\
Enable
CheckedValue = 1

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Internet Explorer\AdvancedOptions\!CNS\
Enable
UncheckedValue = {Random number}

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Internet Explorer\AdvancedOptions\!CNS\
Enable
Text = Enable japanese keywords

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Internet Explorer\AdvancedOptions\!CNS\
Enable
PlugUIText = @{Malware file path and name},-115

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Internet Explorer\AdvancedOptions\!CNS\
Hint
Type = checkbox

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Internet Explorer\AdvancedOptions\!CNS\
Hint
HKeyRoot = {Random number}

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Internet Explorer\AdvancedOptions\!CNS\
Hint
RegPath = SOFTWARE\Microsoft\Internet Explorer\Main

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Internet Explorer\AdvancedOptions\!CNS\
Hint
ValueName = CNSHint

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Internet Explorer\AdvancedOptions\!CNS\
Hint
DefaultValue = 1

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Internet Explorer\AdvancedOptions\!CNS\
Hint
CheckedValue = 1

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Internet Explorer\AdvancedOptions\!CNS\
Hint
UncheckedValue = {Random number}

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Internet Explorer\AdvancedOptions\!CNS\
Hint
Text = Show hint at address bar

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Internet Explorer\AdvancedOptions\!CNS\
Hint
PlugUIText = @{Malware file path and name},-116

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Internet Explorer\AdvancedOptions\!CNS\
Menu
Type = checkbox

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Internet Explorer\AdvancedOptions\!CNS\
Menu
HKeyRoot = {Random number}

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Internet Explorer\AdvancedOptions\!CNS\
Menu
RegPath = SOFTWARE\Microsoft\Internet Explorer\Main

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Internet Explorer\AdvancedOptions\!CNS\
Menu
ValueName = CNSMenu

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Internet Explorer\AdvancedOptions\!CNS\
Menu
DefaultValue = {Random number}

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Internet Explorer\AdvancedOptions\!CNS\
Menu
CheckedValue = 1

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Internet Explorer\AdvancedOptions\!CNS\
Menu
UncheckedValue = {Random number}

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Internet Explorer\AdvancedOptions\!CNS\
Menu
Text = Add "visit japanese keywords" in context menu ( need restart IE )

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Internet Explorer\AdvancedOptions\!CNS\
Menu
PlugUIText = @{Malware file path and name},-502

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Internet Explorer\AdvancedOptions\!CNS\
AutoUpdate
Type = checkbox

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Internet Explorer\AdvancedOptions\!CNS\
AutoUpdate
HKeyRoot = {Random number}

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Internet Explorer\AdvancedOptions\!CNS\
AutoUpdate
RegPath = SOFTWARE\Microsoft\Internet Explorer\Main

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Internet Explorer\AdvancedOptions\!CNS\
AutoUpdate
ValueName = CNSAutoUpdate

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Internet Explorer\AdvancedOptions\!CNS\
AutoUpdate
DefaultValue = 1

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Internet Explorer\AdvancedOptions\!CNS\
AutoUpdate
CheckedValue = 1

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Internet Explorer\AdvancedOptions\!CNS\
AutoUpdate
UncheckedValue = {Random number}

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Internet Explorer\AdvancedOptions\!CNS\
AutoUpdate
Text = Auto upgrade without notification

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Internet Explorer\AdvancedOptions\!CNS\
AutoUpdate
PlugUIText = @{Malware file path and name},-512

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CnsHelper.CH.1
= JWord

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CnsHelper.CH.1\CLSID
= {Random characters}

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CnsHelper.CH
= JWord

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CnsHelper.CH\CLSID
= {Random characters}

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CnsHelper.CH\CurVer
= CnsHelper.CH.1

Other Details

This Adware adds the following registry keys:

HKEY_LOCAL_MACHINE\SOFTWARE\{Random number}

HKEY_LOCAL_MACHINE\SOFTWARE\{Random number}\
CnsMin

HKEY_CURRENT_USER\Software\{Random number}

HKEY_CURRENT_USER\Software\{Random number}\
CnsMin

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
CnsMin

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Internet Explorer\AdvancedOptions\!CNS

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Internet Explorer\AdvancedOptions\!CNS\
Enable

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Internet Explorer\AdvancedOptions\!CNS\
Hint

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Internet Explorer\AdvancedOptions\!CNS\
Menu

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Internet Explorer\AdvancedOptions\!CNS\
AutoUpdate

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CnsHelper.CH.1

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CnsHelper.CH.1\CLSID

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CnsHelper.CH

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CnsHelper.CH\CLSID

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CnsHelper.CH\CurVer

It connects to the following possibly malicious URL:

  • www.{BLOCKED}d.jp
  • support.{BLOCKED}t.jp
  • search.{BLOCKED}d.jp

  SOLUTION

Minimum Scan Engine: 9.850
SSAPI PATTERN File: 2.260.00
SSAPI PATTERN Date: 13 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 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\Internet Explorer\Main
    • CNSReset = {Random numbers}
  • In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main
    • CNSEnable = 1
  • In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main
    • CNSHint = 1
  • In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main
    • CNSList = 1
  • In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main
    • CNSMenu = {Random numbers}
  • In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main
    • CNSAutoUpdate = 1
  • In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main
    • Use Custom Search URL = 0
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Internet Explorer\Search
    • CustomizeSearch = http://search.{BLOCKED}d.jp/jwd_sb_srchcust.htm?ielang={Random characters}
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Internet Explorer\Search
    • SearchAssistant = http://search.{BLOCKED}d.jp/jwd_sb_srchasst.htm?ielang={Random characters}
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Internet Explorer\Extensions\{Random characters}
    • CLSID = {Random characters}
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Internet Explorer\Extensions\{Random characters}
    • ButtonText = Japanese Keywords Homepage
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Internet Explorer\Extensions\{Random characters}
    • HotIcon = {Malware file path}\jwordhot.ico
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Internet Explorer\Extensions\{Random characters}
    • Icon = {Malware file path}\jword.ico
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Internet Explorer\Extensions\{Random characters}
    • DefaultVisible = yes
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Internet Explorer\Extensions\{Random characters}
    • Exec = http://www.{BLOCKED}d.jp/intro/?partner=AP&type=lk&frm=iebutton
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • CnsMin = Rundll32.exe {Malware file path and name},Rundll32

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_LOCAL_MACHINE\SOFTWARE
    • {Random number}
  • In HKEY_CURRENT_USER\Software
    • {Random number}
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall
    • CnsMin
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Internet Explorer\AdvancedOptions
    • !CNS
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes
    • CnsHelper.CH.1
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes
    • CnsHelper.CH

Step 6

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.
  • {Malware file path}\jword.ico
  • {Malware file path}\jwordhot.ico
  • %Common Programs%\Japanese keywords\Japanese Keyword Setting.url
  • %Common Programs%\Japanese keywords\About Japanese Keyword.url
  • %Common Programs%\Japanese keywords\Uninstall.lnk

Step 7

Restart in normal mode and scan your computer with your Trend Micro product for files detected as Adware.Win32.CnsMin.B. 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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