Analysis by: Neljorn Nathaniel Aguas
ALIASES:

Win32/Toolbar.MyWebSearch.BA potentially unwanted application, a variant of Win32/Toolbar.MyWebSearch.AY potentially unwanted application (NOD32)

 PLATFORM:

Windows

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

  • Threat Type: Potentially Unwanted Application

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

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

This Potentially Unwanted Application 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.

  TECHNICAL DETAILS

File Size: 375,216 bytes
File Type: EXE
Initial Samples Received Date: 10 Dec 2024
Payload: Connects to URLs/IPs, Drops files, Modifies system registry

Arrival Details

This Potentially Unwanted Application 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 Potentially Unwanted Application adds the following folders:

  • %User Temp%\nss{4 Random Hex}.tmp → deleted after installation

(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 drops the following files:

  • %User Temp%\nss{4 Random Hex}.tmp\nsDialogs.dll → deleted after installation
  • %User Temp%\nss{4 Random Hex}.tmp\System.dll → deleted after installation
  • %User Temp%\nss{4 Random Hex}.tmp\reporting → deleted after installation
  • %User Temp%\nss{4 Random Hex}.tmp\EasyPDFCombine_1460754060782.bmp → deleted after installation
  • %User Temp%\nss{4 Random Hex}.tmp\cancel_blue_1473354968093.bmp → deleted after installation
  • %User Temp%\nss{4 Random Hex}.tmp\Install_ENG_1435255545043.bmp → deleted after installation
  • %User Temp%\nss{4 Random Hex}.tmp\installerParams → deleted after installation
  • %User Temp%\nss{4 Random Hex}.tmp\MIP-epc-03_1458240142933.bmp → deleted after installation
  • %AppDataLocal%\EasyPDFCombineTooltab\TooltabExtension.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).. %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).)

Other System Modifications

This Potentially Unwanted Application adds the following registry entries:

HKEY_CURRENT_USER\Software\EasyPDFCombine
Start Page = http://{BLOCKED}ay.com/easypdfcombine/s20680/index.html?n=78A5A320&p2=^BSB^mni000^S20680&ptb=2DE8C453-6AD3-4523-AE52-5479A5E4C950&coid=f56ab671d2934d2185a675dc0eae6174

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Uninstall\
EasyPDFCombineTooltab Uninstall Internet Explorer
DisplayName = EasyPDFCombine Internet Explorer Homepage and New Tab

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

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

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Uninstall\
EasyPDFCombineTooltab Uninstall Internet Explorer
HelpLink = http://{BLOCKED}dspark.com/

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Uninstall\
EasyPDFCombineTooltab Uninstall Internet Explorer
URLInfoAbout = http://{BLOCKED}dspark.com/

HKEY_CURRENT_USER\Software\EasyPDFCombine
UnInstallSurveyUrl = http://{BLOCKED}ay.com/uninstall.jhtml?surveyUrl=http%3A%2F%2Fwww.research.net%2Fr%2FHYSCVNM%3Fc%3D2DE8C453-6AD3-4523-AE52-5479A5E4C950%26ptb%3D^BSB^mni000^S20680

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

HKEY_CURRENT_USER\Software\EasyPDFCombine

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

It modifies the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Main
Start Page = http://{BLOCKED}ay.com/easypdfcombine/s20680/index.html?n=78A5A320&p2=^BSB^mni000^S20680&ptb=2DE8C453-6AD3-4523-AE52-5479A5E4C950&coid=f56ab671d2934d2185a675dc0eae6174

(Note: The default value data of the said registry entry is (Default Start Page}.)

Download Routine

This Potentially Unwanted Application connects to the following URL(s) to download its component file(s):

  • http://{BLOCKED}ay.com/easypdfcombine/s20680/assets/1579322917672/ie8.js
  • http://{BLOCKED}ay.com/easypdfcombine/s20680/assets/1579322917672/app.js
  • http://{BLOCKED}icimgfarm.com/images/vicinio/chrome/spent/images/favicon/BSB.ico

Other Details

This Potentially Unwanted Application connects to the following website to send and receive information:

  • http://{BLOCKED}dspark.com/anx.gif?anxa=CAPDownloadProcess&anxe=InstallerFinished&tbUID=B3F25076-F8E7-44DA-924A-EEBA895221D8&tbVer=&platform=vicinio&anxv=2.7.1.1000&anxd=2017-03-16&coid=9e5800ecb3a1432388eab72a4c47a72c&refPartner=^BSB^mni000^S20680&refSub=&anxl=en-US&anxr=2006434501&refCobrand=BSB&refCampaign=mni000&refTrack=S20680&refCountry=
  • http://{BLOCKED}icimgfarm.com/images/webtooltab/ttdetect-2/prd/ttdetect.html
  • https://{BLOCKED}b.ask.com/anx.gif?anxuu=28B33D7D-9710-4BBF-83B4-1405A4A90AD0&anxa=WebTooltab&anxv=webtooltab-2.1.1&anxd=-&anxsn=&anxu=http%3A%2F%2Fhp.myway.com%2Feasypdfcombine%2Fs20680%2Findex.html&anxl=en&anxlv=0&anxrd=none&anxrp=-&anxrk=-&anxrm=-&anxrb=-&anxrc=-&anxrs=-&anxsq=2&anxt=B3F25076-F8E7-44DA-924A-EEBA895221D8&anxp=%5EBSB%5Emni000%5ES20680&anxsi=&buid=492121ba-bb94-4055-bf71-b09d57a96964&pageType=tab&productData=%7B%22coid%22%3A%229e5800ecb3a1432388eab72a4c47a72c%22%2C%22pageLoad%22%3A1%7D&anxe=Heartbeat&anxr=1501828281
  • https://{BLOCKED}b.ask.com/anx.gif?anxuu=28B33D7D-9710-4BBF-83B4-1405A4A90AD0&anxa=WebTooltab&anxv=webtooltab-2.1.1&anxd=-&anxsn=&anxu=http%3A%2F%2Fhp.myway.com%2Feasypdfcombine%2Fs20680%2Findex.html&anxl=en&anxlv=1733920495812&anxrd=none&anxrp=-&anxrk=-&anxrm=-&anxrb=-&anxrc=-&anxrs=-&anxsq=4&anxt=B3F25076-F8E7-44DA-924A-EEBA895221D8&anxp=%5EBSB%5Emni000%5ES20680&anxsi=&buid=492121ba-bb94-4055-bf71-b09d57a96964&pageType=tab&kpi=pageView&productData=%7B%22queryString%22%3A%7B%22n%22%3A%2278A5A320%22%2C%22coid%22%3A%229e5800ecb3a1432388eab72a4c47a72c%22%2C%22dpr%22%3A%22%22%2C%22pixelUrl%22%3A%22%22%2C%22trs%22%3A%22wtt%22%2C%22cwsid%22%3A%22%22%7D%2C%22innerWidth%22%3A788%2C%22innerHeight%22%3A420%2C%22userFontSize%22%3A16%2C%22pageLoad%22%3A1%7D&anxe=PageView&anxr=801975463
  • https://{BLOCKED}b.ask.com/anx.gif?anxuu=28B33D7D-9710-4BBF-83B4-1405A4A90AD0&anxa=CAPSearch&anxv=webtooltab-2.1.1&anxd=-&anxsn=&anxu=http%3A%2F%2Fhp.myway.com%2Feasypdfcombine%2Fs20680%2Findex.html&anxl=en&anxlv=1733920495812&anxrd=none&anxrp=-&anxrk=-&anxrm=-&anxrb=-&anxrc=-&anxrs=-&anxsq=5&anxt=B3F25076-F8E7-44DA-924A-EEBA895221D8&anxp=%5EBSB%5Emni000%5ES20680&anxsi=&buid=492121ba-bb94-4055-bf71-b09d57a96964&pageType=tab&productData=%7B%22pageLoad%22%3A1%7D&anxe=TabPageView&anxr=1504087953
  • https://{BLOCKED}b.ask.com/anx.gif?anxuu=28B33D7D-9710-4BBF-83B4-1405A4A90AD0&anxa=CAPOne&anxv=webtooltab-2.1.1&anxd=-&anxsn=&anxu=http%3A%2F%2Fhp.myway.com%2Feasypdfcombine%2Fs20680%2Findex.html&anxl=en&anxlv=1733920495797&anxrd=none&anxrp=-&anxrk=-&anxrm=-&anxrb=-&anxrc=-&anxrs=-&anxsq=3&anxt=B3F25076-F8E7-44DA-924A-EEBA895221D8&anxp=%5EBSB%5Emni000%5ES20680&anxsi=&buid=492121ba-bb94-4055-bf71-b09d57a96964&pageType=tab&anxtv=webtooltab-2.1.1&fParameter=00000050&coid=9e5800ecb3a1432388eab72a4c47a72c&productData=%7B%22pageLoad%22%3A1%7D&anxe=ToolbarConfig&anxr=1736166346

It does the following:

  • It is an installer for the following toolbar:
    • EasyPDFCombine v2.7.1.1000
  • It sets the default start page and new tab into the following URL:
    • http://{BLOCKED}ay.com/easypdfcombine/s20680/index.html?n=78A5A320&p2=^BSB^mni000^S20680&ptb=2DE8C453-6AD3-4523-AE52-5479A5E4C950&coid=f56ab671d2934d2185a675dc0eae6174
  • The toolbar contains the following additional tools:
    • Search Bar using the following URL:
      • https://{BLOCKED}ay.com/
    • EasyPDFCombine with the following URL:
      • https://{BLOCKED}ine.com/ → tool to combine multiple PDF files into one
    • PDF Converter using the following URL:
      • https://{BLOCKED}vert.com/
    • Share Files by redirecting the user to the following selected URL:
      • https://wetransfer.com/ → WeTransfer
      • https://www.sendspace.com/ → Sendspace
      • https://free.mailbigfile.com/ → MailBigFile
      • https://www.transferbigfiles.com/ → TransferBigFiles.com
      • https://www.dropsend.com/ → Dropsend
      • http://ge.tt/ → Get.tt
      • https://droplr.com/ → Droplr
      • http://www.senduit.com/ → Senduit
      • https://wikisend.com/ → Wikisend
      • http://www.filedropper.com/ → File Dropper
      • https://www.files.com/ → Files.com
      • http://www.fileconvoy.com/ → File Convoy
      • https://www.slideshare.net/ → SlideShare
    • Language Tools by redirecting the user to the following selected URL:
      • www.dictionary.reference.com
      • www.thesaurus.com
      • www.britannica.com
      • https://translate.google.com
    • Weather Report from AccuWeather

  SOLUTION

Minimum Scan Engine: 9.800
SSAPI PATTERN File: 2.789.00
SSAPI PATTERN Date: 12 Dec 2024

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

Restore this modified 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 = http://{BLOCKED}ay.com/easypdfcombine/s20680/index.html?n=78A5A320&p2=^BSB^mni000^S20680&ptb=2DE8C453-6AD3-4523-AE52-5479A5E4C950&coid=f56ab671d2934d2185a675dc0eae6174

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\EasyPDFCombine
    • Start Page = http://{BLOCKED}ay.com/easypdfcombine/s20680/index.html?n=78A5A320&p2=^BSB^mni000^S20680&ptb=2DE8C453-6AD3-4523-AE52-5479A5E4C950&coid=f56ab671d2934d2185a675dc0eae6174
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Uninstall\EasyPDFCombineTooltab Uninstall Internet Explorer
    • DisplayName = EasyPDFCombine Internet Explorer Homepage and New Tab
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Uninstall\EasyPDFCombineTooltab Uninstall Internet Explorer
    • UninstallString = Rundll32.exe "%AppDataLocal%\EasyPDFCombineTooltab\TooltabExtension.dll" U uninstall:EasyPDFCombine
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Uninstall\EasyPDFCombineTooltab Uninstall Internet Explorer
    • Publisher = Mindspark Interactive Network, Inc.
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Uninstall\EasyPDFCombineTooltab Uninstall Internet Explorer
    • HelpLink = http://{BLOCKED}dspark.com/
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Uninstall\EasyPDFCombineTooltab Uninstall Internet Explorer
    • URLInfoAbout = http://{BLOCKED}dspark.com/
  • In HKEY_CURRENT_USER\Software\EasyPDFCombine
    • UnInstallSurveyUrl = http://{BLOCKED}ay.com/uninstall.jhtml?surveyUrl=http%3A%2F%2Fwww.research.net%2Fr%2FHYSCVNM%3Fc%3D2DE8C453-6AD3-4523-AE52-5479A5E4C950%26ptb%3D^BSB^mni000^S20680

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. 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\
    • EasyPDFCombine
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Uninstall\
    • EasyPDFCombineTooltab Uninstall Internet Explorer

Step 6

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.
  • %User Temp%\nss{4 Random Hex}.tmp\nsDialogs.dll
  • %User Temp%\nss{4 Random Hex}.tmp\System.dll
  • %User Temp%\nss{4 Random Hex}.tmp\reporting
  • %User Temp%\nss{4 Random Hex}.tmp\EasyPDFCombine_1460754060782.bmp
  • %User Temp%\nss{4 Random Hex}.tmp\cancel_blue_1473354968093.bmp
  • %User Temp%\nss{4 Random Hex}.tmp\Install_ENG_1435255545043.bmp
  • %User Temp%\nss{4 Random Hex}.tmp\installerParams
  • %User Temp%\nss{4 Random Hex}.tmp\MIP-epc-03_1458240142933.bmp
  • %AppDataLocal%\EasyPDFCombineTooltab\TooltabExtension.dll

Step 7

Search and delete this folder

[ 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%\nss{4 Random Hex}.tmp

Step 8

Scan your computer with your Trend Micro product to delete files detected as PUA.Win32.MyWebSearch.C. 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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