Analysis by: Maria Emreen Viray
ALIASES:

Win32/Toolbar.MyWebSearch.BA (NOD32); PUA/MyWebSearch.Gen, PUA/MyWebSearch.hrd, PUA/MyWebSearch.hrc (ANTIVIR)

 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

Infection Channel: Downloaded from the Internet, Dropped by other malware

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.

It connects to certain websites to send and receive information. It redirects browsers to certain sites.

  TECHNICAL DETAILS

File Size: 386,608 bytes
File Type: EXE
Memory Resident: No
Initial Samples Received Date: 28 Apr 2021
Payload: Connects to URLs/IPs, Displays graphics/image, Drops files

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:

  • Temporarily files (deleted afterwards):
    • %User temp%\nsvC{random}.tmp\nsDialogs.dll
    • %User temp%\nsvC{random}.tmp\System.dll
    • %User temp%\nsvC{random}.tmp\CouponXplorer_msi_bg-copy_1501853470322.bmp
    • %User temp%\nsvC{random}.tmp\cancel_blue_1473350537366.bmp
    • %User temp%\nsvC{random}.tmp\Install_ENG_1435255545043.bmp
    • %User temp%\Cab{random}.tmp
    • %User temp%\Tar{random}.tmp
    • %AppDataLocalLow%\Microsoft\CryptnetUrlCache\MetaData\F0ACCF77CDCBFF39F6191887F6D2D357
    • %AppDataLocalLow%\Microsoft\CryptnetUrlCache\Content\F0ACCF77CDCBFF39F6191887F6D2D357
    • %User temp%\nsvC{random}.tmp\installerParams
    • %User temp%\nsvC{random}.tmp\reporting
    • %User temp%\nsvC{random}.tmp\CouponXplorer_msi_bg-copy_1501853485098.bmp
  • %AppDataLocal%\CouponXplorerTooltab\TooltabExtension.dll
  • %Application Data%\Microsoft\Windows\Cookies\{Username}@tb.ask[{#}].txt

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

Other System Modifications

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

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Main
Start Page = https://hp.{BLOCKED}y.com/couponxplorer/ttab02/index.html?{random}

HKEY_CURRENT_USER\Software\CouponXplorer
Start Page = https://hp.{BLOCKED}y.com/couponxplorer/ttab02/index.html?{random}

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\TabbedBrowsing
NewTabPageShow = 1

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Uninstall\
CouponXplorerTooltab Uninstall Internet Explorer
DisplayName = CouponXplorer Internet Explorer Homepage and New Tab

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Uninstall\
CouponXplorerTooltab Uninstall Internet Explorer
UninstallString = Rundll32.exe "%AppDataLocal%\CouponXplorerTooltab\TooltabExtension.dll" U uninstall:CouponXplorer

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Uninstall\
CouponXplorerTooltab Uninstall Internet Explorer
Publisher = Mindspark Interactive Network, Inc.

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Uninstall\
CouponXplorerTooltab Uninstall Internet Explorer
HelpLink = http://support.{BLOCKED}ark.com/

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Uninstall\
CouponXplorerTooltab Uninstall Internet Explorer
URLInfoAbout = http://support.{BLOCKED}ark.com/

HKEY_CURRENT_USER\Software\CouponXplorer
UnInstallSurveyUrl = https://@{downloadDomain}.dl.{BLOCKED}y.com/uninstall.jhtml?{random}

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

HKEY_CURRENT_USER\Software\CouponXplorer

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\TabbedBrowsing

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Uninstall

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Uninstall\
CouponXplorerTooltab Uninstall Internet Explorer

Other Details

This Adware connects to the following website to send and receive information:

  • It sends the installation process to the following URL via HTTP GET:
    • https://anx.{BLOCKED}ark.com/anx.gif?anxa=CAPDownloadProcess&anxe=Error&errorCode=-16&errorType=nsisError&errorDetails=&platform=vicinio&anxv=2.7.1.3000&anxd=2019-11-28&coid=&refPartner=^AFA^mni000^TTAB02&refSub=&anxl={language}&anxr=-2011124004&refCobrand=AFA&refCampaign=mni000&refTrack=TTAB02&refCountry=
    • https://anx.{BLOCKED}ark.com/anx.gif?anxa=CAPDownloadProcess&anxe=Error&errorCode=-8&errorType=nsisError&errorDetails={malware name}&platform=vicinio&anxv=2.7.1.3000&anxd=2019-11-28&coid={generated ID}&refPartner=^AFA^mni000^TTAB02&refSub=&anxl=en-US&anxr=-{random}&refCobrand=AFA&refCampaign=mni000&refTrack=TTAB02&refCountry=
    • https://dp.tb.{BLOCKED}k.com/installerParams.jhtml?coId={generated ID}
    • https://anx.{BLOCKED}ark.com/anx.gif?anxa=CAPDownloadProcess&anxe=InstallerInvoked&platform=vicinio&anxv=2.7.1.3000&anxd=2019-11-28&coid={generated ID}&refPartner=^AFA^mni000^TTAB02&refSub=&anxl=en-US&anxr={random}&refCobrand=AFA&refCampaign=mni000&refTrack=TTAB02&refCountry=
    • https://anx.{BLOCKED}ark.com/anx.gif?anxa=CAPDownloadProcess&anxe=Error&errorCode=-11&errorType=nsisError&errorDetails=File+Not+Found+%28404%29&platform=vicinio&anxv=2.7.1.3000&anxd=2019-11-28&coid={generated ID}&refPartner=^AFA^mni000^TTAB02&refSub=&anxl=en-US&anxr={random}&refCobrand=AFA&refCampaign=mni000&refTrack=TTAB02&refCountry=
    • https://anx.{BLOCKED}ark.com/anx.gif?anxa=CAPDownloadProcess&anxe=InstallerFinished&tbUID=A7128FC7-A538-40A9-A810-68D7107C1511&tbVer=&platform=vicinio&anxv=2.7.1.3000&anxd=2019-11-28&coid={generated ID}&refPartner=^AFA^mni000^TTAB02&refSub=&anxl=en-US&anxr={random}&refCobrand=AFA&refCampaign=mni000&refTrack=TTAB02&refCountry=

It displays the following images:

  • Ad displayed upon execution:

    prompts user to install CouponXplorer as Internet Explorer's default Search Engine

It redirects browsers to the following sites:

  • https://hp.myway.com/couponxplorer/ttab02/index.html?{random}
  • https://hp.myway.com/unsupported/myway/index.html?{random}

  SOLUTION

Minimum Scan Engine: 9.800
SSAPI PATTERN File: 2.403.00
SSAPI PATTERN Date: 29 Apr 2021

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

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
    • Start Page = https://hp.{BLOCKED}y.com/couponxplorer/ttab02/index.html?{random}
  • In HKEY_CURRENT_USER\Software\CouponXplorer
    • Start Page = https://hp.{BLOCKED}y.com/couponxplorer/ttab02/index.html?{random} 
  • In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\TabbedBrowsing
    • NewTabPageShow = 1
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Uninstall\CouponXplorerTooltab Uninstall Internet Explorer
    • DisplayName = CouponXplorer Internet Explorer Homepage and New Tab
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Uninstall\CouponXplorerTooltab Uninstall Internet Explorer
    • UninstallString = Rundll32.exe %AppDataLocal%\CouponXplorerTooltab\TooltabExtension.dll U uninstall:CouponXplorer
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Uninstall\CouponXplorerTooltab Uninstall Internet Explorer
    • Publisher = Mindspark Interactive Network, Inc.
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Uninstall\CouponXplorerTooltab Uninstall Internet Explorer
    • HelpLink = http://support.{BLOCKED}ark.com/
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Uninstall\CouponXplorerTooltab Uninstall Internet Explorer
    • URLInfoAbout = http://support.{BLOCKED}ark.com/ /
  • In HKEY_CURRENT_USER\Software\CouponXplorer
    • UnInstallSurveyUrl = https://@{downloadDomain}.dl.{BLOCKED}y.com/uninstall.jhtml?c=BD5B7D82-74D6-4F00-8A91-31B7501AA2A1&ptb=^AFA^mni000^TTAB02

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. Before you could do this, you must restart in Safe Mode. For instructions on how to do this, you may refer to this page If the preceding step requires you to restart in safe mode, you may proceed to edit the system registry.

  • In HKEY_CURRENT_USER\Software\CouponXplorer
  • In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\TabbedBrowsing
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Uninstall
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Uninstall\CouponXplorerTooltab Uninstall Internet Explorer

Step 5

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.  
  • %AppDataLocal%\CouponXplorerTooltab\TooltabExtension.dll
  • %Application Data%\Microsoft\Windows\Cookies\{Username}@tb.ask[{#}].txt

Step 6

Scan your computer with your Trend Micro product to delete files detected as Adware.Win32.CouponXplorer.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 the following Trend Micro Support pages for more information:


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