Analysis by: Mohammed Malubay
ALIASES:

a variant of MSIL/WebCompanion.C 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 uses a user interface (UI).

  TECHNICAL DETAILS

File Size: 512,464 bytes
File Type: EXE
Initial Samples Received Date: 22 Jul 2020
Payload: Connects to URLs/IPs, Displays windows

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:

  • %Program Files%\Lavasoft
  • %Program Files%\Lavasoft\Web Companion
  • %Program Files%\Lavasoft\Web Companion\Application
  • %Program Files%\Lavasoft\Web Companion\Application\de-DE
  • %Program Files%\Lavasoft\Web Companion\Application\en-US
  • %Program Files%\Lavasoft\Web Companion\Application\es-ES
  • %Program Files%\Lavasoft\Web Companion\Application\fr-CA
  • %Program Files%\Lavasoft\Web Companion\Application\it-IT
  • %Program Files%\Lavasoft\Web Companion\Application\ja-JP
  • %Program Files%\Lavasoft\Web Companion\Application\pt-BR
  • %Program Files%\Lavasoft\Web Companion\Application\ru-RU
  • %Program Files%\Lavasoft\Web Companion\Application\tr-TR
  • %Program Files%\Lavasoft\Web Companion\Application\x64
  • %Program Files%\Lavasoft\Web Companion\Application\x86
  • %Program Files%\Lavasoft\Web Companion\Application\zh-CHS
  • %Program Files%\Lavasoft\Web Companion\Application\zh-Hans
  • %ProgramData%\Lavasoft\
  • %ProgramData%\Lavasoft\Web Companion
  • %ProgramData%\Lavasoft\Web Companion\Options

(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).. %ProgramData% is a version of the Program Files folder where any user on a multi-user computer can make changes to programs. This contains application data for all users. This is usually C:\ProgramData on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit), or C:\Documents and Settings\All Users on Windows Server 2003(32-bit), 2000(32-bit) and XP.)

It drops the following files:

  • %Program Files%\Lavasoft\Web Companion\Application\Ad-Aware Web Companion.exe
  • %Program Files%\Lavasoft\Web Companion\Application\BCUEngineS.dll
  • %Program Files%\Lavasoft\Web Companion\Application\BCUSDK.dll
  • %Program Files%\Lavasoft\Web Companion\Application\DotNetZip.dll
  • %Program Files%\Lavasoft\Web Companion\Application\Esent.Interop.dll
  • %Program Files%\Lavasoft\Web Companion\Application\Extension\@wcextensionff.xpi
  • %Program Files%\Lavasoft\Web Companion\Application\ICSharpCode.SharpZipLib.dll
  • %Program Files%\Lavasoft\Web Companion\Application\Interop.IWshRuntimeLibrary.dll
  • %Program Files%\Lavasoft\Web Companion\Application\Interop.LavasoftTcpServiceLib.dll
  • %Program Files%\Lavasoft\Web Companion\Application\Interop.SHDocVw.dll
  • %Program Files%\Lavasoft\Web Companion\Application\Interop.Shell32.dll
  • %Program Files%\Lavasoft\Web Companion\Application\Interop.WUApiLib.dll
  • %Program Files%\Lavasoft\Web Companion\Application\Ionic.Zip.dll
  • %Program Files%\Lavasoft\Web Companion\Application\LZ4.dll
  • %Program Files%\Lavasoft\Web Companion\Application\Lavasoft.AppCore.dll
  • %Program Files%\Lavasoft\Web Companion\Application\Lavasoft.Automation.dll
  • %Program Files%\Lavasoft\Web Companion\Application\Lavasoft.CSharp.Utilities.dll
  • %Program Files%\Lavasoft\Web Companion\Application\Lavasoft.Compression.dll
  • %Program Files%\Lavasoft\Web Companion\Application\Lavasoft.Events.dll
  • %Program Files%\Lavasoft\Web Companion\Application\Lavasoft.Extension.dll
  • %Program Files%\Lavasoft\Web Companion\Application\Lavasoft.IEController.dll
  • %Program Files%\Lavasoft\Web Companion\Application\Lavasoft.Omni.dll
  • %Program Files%\Lavasoft\Web Companion\Application\Lavasoft.SearchProtect.Business.dll
  • %Program Files%\Lavasoft\Web Companion\Application\Lavasoft.SearchProtect.Repositories.dll
  • %Program Files%\Lavasoft\Web Companion\Application\Lavasoft.Settings.dll
  • %Program Files%\Lavasoft\Web Companion\Application\Lavasoft.SysInfo.dll
  • %Program Files%\Lavasoft\Web Companion\Application\Lavasoft.Utils.SqlLite.dll
  • %Program Files%\Lavasoft\Web Companion\Application\Lavasoft.Utils.dll
  • %Program Files%\Lavasoft\Web Companion\Application\Lavasoft.WCAssistant.Service.Logger.dll
  • %Program Files%\Lavasoft\Web Companion\Application\Lavasoft.WCAssistant.WcfService.dll
  • %Program Files%\Lavasoft\Web Companion\Application\Lavasoft.WCAssistant.WinService.exe
  • %Program Files%\Lavasoft\Web Companion\Application\Lavasoft.WCAssistant.WinService.exe.config
  • %Program Files%\Lavasoft\Web Companion\Application\Lavasoft.adblocker.dll
  • %Program Files%\Lavasoft\Web Companion\Application\Microsoft.mshtml.dll
  • %Program Files%\Lavasoft\Web Companion\Application\MozCompressor.dll
  • %Program Files%\Lavasoft\Web Companion\Application\Newtonsoft.Json.dll
  • %Program Files%\Lavasoft\Web Companion\Application\System.Data.SQLite.dll
  • %Program Files%\Lavasoft\Web Companion\Application\WcCommunication.exe
  • %Program Files%\Lavasoft\Web Companion\Application\WcCommunication.exe.config
  • %Program Files%\Lavasoft\Web Companion\Application\WebCompanion.Loader.exe
  • %Program Files%\Lavasoft\Web Companion\Application\WebCompanion.exe
  • %Program Files%\Lavasoft\Web Companion\Application\WebCompanion.exe.config
  • %Program Files%\Lavasoft\Web Companion\Application\WebCompanionExtensionIE.dll
  • %Program Files%\Lavasoft\Web Companion\Application\WebCompanionIcon.ico
  • %Program Files%\Lavasoft\Web Companion\Application\WebCompanionIcon_Pro.ico
  • %Program Files%\Lavasoft\Web Companion\Application\WebCompanionInstaller.exe
  • %Program Files%\Lavasoft\Web Companion\Application\WebCompanionInstaller.exe.config
  • %Program Files%\Lavasoft\Web Companion\Application\WebCompanionInstaller.pdb
  • %Program Files%\Lavasoft\Web Companion\Application\WebcompaionReimageIcon.ico
  • %Program Files%\Lavasoft\Web Companion\Application\de-DE\WebCompanion.resources.dll
  • %Program Files%\Lavasoft\Web Companion\Application\de-DE\WebCompanionInstaller.resources.dll
  • %Program Files%\Lavasoft\Web Companion\Application\en-US\WebCompanion.resources.dll
  • %Program Files%\Lavasoft\Web Companion\Application\en-US\WebCompanionInstaller.resources.dll
  • %Program Files%\Lavasoft\Web Companion\Application\es-ES\WebCompanion.resources.dll
  • %Program Files%\Lavasoft\Web Companion\Application\es-ES\WebCompanionInstaller.resources.dll
  • %Program Files%\Lavasoft\Web Companion\Application\fr-CA\WebCompanion.resources.dll
  • %Program Files%\Lavasoft\Web Companion\Application\fr-CA\WebCompanionInstaller.resources.dll
  • %Program Files%\Lavasoft\Web Companion\Application\it-IT\WebCompanion.resources.dll
  • %Program Files%\Lavasoft\Web Companion\Application\it-IT\WebCompanionInstaller.resources.dll
  • %Program Files%\Lavasoft\Web Companion\Application\ja-JP\WebCompanion.resources.dll
  • %Program Files%\Lavasoft\Web Companion\Application\ja-JP\WebCompanionInstaller.resources.dll
  • %Program Files%\Lavasoft\Web Companion\Application\liblz4.dll
  • %Program Files%\Lavasoft\Web Companion\Application\log4net.dll
  • %Program Files%\Lavasoft\Web Companion\Application\pt-BR\WebCompanion.resources.dll
  • %Program Files%\Lavasoft\Web Companion\Application\pt-BR\WebCompanionInstaller.resources.dll
  • %Program Files%\Lavasoft\Web Companion\Application\ru-RU\WebCompanion.resources.dll
  • %Program Files%\Lavasoft\Web Companion\Application\ru-RU\WebCompanionInstaller.resources.dll
  • %Program Files%\Lavasoft\Web Companion\Application\tr-TR\WebCompanion.resources.dll
  • %Program Files%\Lavasoft\Web Companion\Application\tr-TR\WebCompanionInstaller.resources.dll
  • %Program Files%\Lavasoft\Web Companion\Application\ucrtbased.dll
  • %Program Files%\Lavasoft\Web Companion\Application\vcruntime140d.dll
  • %Program Files%\Lavasoft\Web Companion\Application\x64\SQLite.Interop.dll
  • %Program Files%\Lavasoft\Web Companion\Application\x86\SQLite.Interop.dll
  • %Program Files%\Lavasoft\Web Companion\Application\zh-CHS\WebCompanionInstaller.resources.dll
  • %Program Files%\Lavasoft\Web Companion\Application\zh-Hans\WebCompanion.resources.dll
  • %ProgramData%\Lavasoft\Web Companion\Options\Statistics.txt → contains install id

(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).. %ProgramData% is a version of the Program Files folder where any user on a multi-user computer can make changes to programs. This contains application data for all users. This is usually C:\ProgramData on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit), or C:\Documents and Settings\All Users on Windows Server 2003(32-bit), 2000(32-bit) and XP.)

It adds the following processes:

  • "%User Temp%\wctmp_{random numbers}\WcInstaller.exe" --nanouniqueid={Generated Unique ID} --prod
  • .\WebCompanionInstaller.exe --prod
  • .\WebCompanionInstaller.exe --prod --nanouniqueid={Generated Unique ID} --prod
  • To create the service:
    • "sc.exe" Create "WCAssistantService" binPath= "%Program Files%\Lavasoft\Web Companion\Application\Lavasoft.WCAssistant.WinService.exe" DisplayName= "WC Assistant" start= auto
    • "sc.exe" description "WCAssistantService" "Ad-Aware Web Companion Internet security service"
    • "sc.exe" failure WCAssistantService reset= 30 actions= restart/60000

(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).)

Autostart Technique

This Potentially Unwanted Application adds and runs the following services:

  • Service Name: WCAssistantService
    • Description: Ad-Aware Web Companion Internet security service
    • Path: %Program Files%\Lavasoft\Web Companion\Application\Lavasoft.WCAssistant.WinService.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).)

Other System Modifications

This Potentially Unwanted Application adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Lavasoft\
Web Companion
MachineId = {Generated Machine ID}

Download Routine

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

  • http://s2.{BLOCKED}b.com/MFEwTzBNMEswSTAJBgUrDgMCGgUABBS56bKHAoUD%2BOyl%2B0LhPg9JxyQm4gQUf9Nlp8Ld7LvwMAnzQzn6Aq8zMTMCED141%2Fl2SWCyYX308B7Khio%3D
  • http://s1.{BLOCKED}b.com/pca3-g5.crl
  • http://sv.{BLOCKED}d.com/MFEwTzBNMEswSTAJBgUrDgMCGgUABBQe6LNDJdqx%2BJOp7hVgTeaGFJ%2FCQgQUljtT8Hkzl699g%2B8uK8zKt4YecmYCEDMsr2P3ZGPXNMgj3DuT3Ew%3D
  • http://wc-update-service.{BLOCKED}ft.com/update.asmx
  • http://wcdownloadercdn.{BLOCKED}ft.com/4.9.2159.4024/WcInstaller.exe
  • http://wc-tracking.{BLOCKED}ft.com/Install.asmx

Other Details

This Potentially Unwanted Application adds the following registry keys:

HKEY_LOCAL_MACHINE\SOFTWARE\Lavasoft

HKEY_LOCAL_MACHINE\SOFTWARE\Lavasoft\
Web Companion

It uses the following user interface:

It does the following:

  • It is capable of making default home page and/or default search engine to the following:
    • Bing
    • Yahoo!
    • Yandex
    • Keep current settings
  • It connects to the following URL to access its GUI's design:
    • http://www.{BLOCKED}panion.com/installer/consent_2?culture=en&hp=1&se=1 → contains the installer interface (the instance after clicking install)
    • http://{BLOCKED}panion.com/installer/css/styles.css?1596529652 → contains style config for installer
    • http://wc-tracking.{BLOCKED}ft.com/Install.asmx

  SOLUTION

Minimum Scan Engine: 9.850
SSAPI PATTERN File: 2.317.00
SSAPI PATTERN Date: 30 Jul 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

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_LOCAL_MACHINE\SOFTWARE\Lavasoft\Web Companion
    • MachineId = {Generated Machine ID}

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.

  • In HKEY_LOCAL_MACHINE\SOFTWARE\Lavasoft
    • (null)
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Lavasoft\Web Companion
    • (null)

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%\Lavasoft\Web Companion\Application\Ad-Aware Web Companion.exe
  • %Program Files%\Lavasoft\Web Companion\Application\BCUEngineS.dll
  • %Program Files%\Lavasoft\Web Companion\Application\BCUSDK.dll
  • %Program Files%\Lavasoft\Web Companion\Application\DotNetZip.dll
  • %Program Files%\Lavasoft\Web Companion\Application\Esent.Interop.dll
  • %Program Files%\Lavasoft\Web Companion\Application\Extension\@wcextensionff.xpi
  • %Program Files%\Lavasoft\Web Companion\Application\ICSharpCode.SharpZipLib.dll
  • %Program Files%\Lavasoft\Web Companion\Application\Interop.IWshRuntimeLibrary.dll
  • %Program Files%\Lavasoft\Web Companion\Application\Interop.LavasoftTcpServiceLib.dll
  • %Program Files%\Lavasoft\Web Companion\Application\Interop.SHDocVw.dll
  • %Program Files%\Lavasoft\Web Companion\Application\Interop.Shell32.dll
  • %Program Files%\Lavasoft\Web Companion\Application\Interop.WUApiLib.dll
  • %Program Files%\Lavasoft\Web Companion\Application\Ionic.Zip.dll
  • %Program Files%\Lavasoft\Web Companion\Application\LZ4.dll
  • %Program Files%\Lavasoft\Web Companion\Application\Lavasoft.AppCore.dll
  • %Program Files%\Lavasoft\Web Companion\Application\Lavasoft.Automation.dll
  • %Program Files%\Lavasoft\Web Companion\Application\Lavasoft.CSharp.Utilities.dll
  • %Program Files%\Lavasoft\Web Companion\Application\Lavasoft.Compression.dll
  • %Program Files%\Lavasoft\Web Companion\Application\Lavasoft.Events.dll
  • %Program Files%\Lavasoft\Web Companion\Application\Lavasoft.Extension.dll
  • %Program Files%\Lavasoft\Web Companion\Application\Lavasoft.IEController.dll
  • %Program Files%\Lavasoft\Web Companion\Application\Lavasoft.Omni.dll
  • %Program Files%\Lavasoft\Web Companion\Application\Lavasoft.SearchProtect.Business.dll
  • %Program Files%\Lavasoft\Web Companion\Application\Lavasoft.SearchProtect.Repositories.dll
  • %Program Files%\Lavasoft\Web Companion\Application\Lavasoft.Settings.dll
  • %Program Files%\Lavasoft\Web Companion\Application\Lavasoft.SysInfo.dll
  • %Program Files%\Lavasoft\Web Companion\Application\Lavasoft.Utils.SqlLite.dll
  • %Program Files%\Lavasoft\Web Companion\Application\Lavasoft.Utils.dll
  • %Program Files%\Lavasoft\Web Companion\Application\Lavasoft.WCAssistant.Service.Logger.dll
  • %Program Files%\Lavasoft\Web Companion\Application\Lavasoft.WCAssistant.WcfService.dll
  • %Program Files%\Lavasoft\Web Companion\Application\Lavasoft.WCAssistant.WinService.exe
  • %Program Files%\Lavasoft\Web Companion\Application\Lavasoft.WCAssistant.WinService.exe.config
  • %Program Files%\Lavasoft\Web Companion\Application\Lavasoft.adblocker.dll
  • %Program Files%\Lavasoft\Web Companion\Application\Microsoft.mshtml.dll
  • %Program Files%\Lavasoft\Web Companion\Application\MozCompressor.dll
  • %Program Files%\Lavasoft\Web Companion\Application\Newtonsoft.Json.dll
  • %Program Files%\Lavasoft\Web Companion\Application\System.Data.SQLite.dll
  • %Program Files%\Lavasoft\Web Companion\Application\WcCommunication.exe
  • %Program Files%\Lavasoft\Web Companion\Application\WcCommunication.exe.config
  • %Program Files%\Lavasoft\Web Companion\Application\WebCompanion.Loader.exe
  • %Program Files%\Lavasoft\Web Companion\Application\WebCompanion.exe
  • %Program Files%\Lavasoft\Web Companion\Application\WebCompanion.exe.config
  • %Program Files%\Lavasoft\Web Companion\Application\WebCompanionExtensionIE.dll
  • %Program Files%\Lavasoft\Web Companion\Application\WebCompanionIcon.ico
  • %Program Files%\Lavasoft\Web Companion\Application\WebCompanionIcon_Pro.ico
  • %Program Files%\Lavasoft\Web Companion\Application\WebCompanionInstaller.exe
  • %Program Files%\Lavasoft\Web Companion\Application\WebCompanionInstaller.exe.config
  • %Program Files%\Lavasoft\Web Companion\Application\WebCompanionInstaller.pdb
  • %Program Files%\Lavasoft\Web Companion\Application\WebcompaionReimageIcon.ico
  • %Program Files%\Lavasoft\Web Companion\Application\de-DE\WebCompanion.resources.dll
  • %Program Files%\Lavasoft\Web Companion\Application\de-DE\WebCompanionInstaller.resources.dll
  • %Program Files%\Lavasoft\Web Companion\Application\en-US\WebCompanion.resources.dll
  • %Program Files%\Lavasoft\Web Companion\Application\en-US\WebCompanionInstaller.resources.dll
  • %Program Files%\Lavasoft\Web Companion\Application\es-ES\WebCompanion.resources.dll
  • %Program Files%\Lavasoft\Web Companion\Application\es-ES\WebCompanionInstaller.resources.dll
  • %Program Files%\Lavasoft\Web Companion\Application\fr-CA\WebCompanion.resources.dll
  • %Program Files%\Lavasoft\Web Companion\Application\fr-CA\WebCompanionInstaller.resources.dll
  • %Program Files%\Lavasoft\Web Companion\Application\it-IT\WebCompanion.resources.dll
  • %Program Files%\Lavasoft\Web Companion\Application\it-IT\WebCompanionInstaller.resources.dll
  • %Program Files%\Lavasoft\Web Companion\Application\ja-JP\WebCompanion.resources.dll
  • %Program Files%\Lavasoft\Web Companion\Application\ja-JP\WebCompanionInstaller.resources.dll
  • %Program Files%\Lavasoft\Web Companion\Application\liblz4.dll
  • %Program Files%\Lavasoft\Web Companion\Application\log4net.dll
  • %Program Files%\Lavasoft\Web Companion\Application\pt-BR\WebCompanion.resources.dll
  • %Program Files%\Lavasoft\Web Companion\Application\pt-BR\WebCompanionInstaller.resources.dll
  • %Program Files%\Lavasoft\Web Companion\Application\ru-RU\WebCompanion.resources.dll
  • %Program Files%\Lavasoft\Web Companion\Application\ru-RU\WebCompanionInstaller.resources.dll
  • %Program Files%\Lavasoft\Web Companion\Application\tr-TR\WebCompanion.resources.dll
  • %Program Files%\Lavasoft\Web Companion\Application\tr-TR\WebCompanionInstaller.resources.dll
  • %Program Files%\Lavasoft\Web Companion\Application\ucrtbased.dll
  • %Program Files%\Lavasoft\Web Companion\Application\vcruntime140d.dll
  • %Program Files%\Lavasoft\Web Companion\Application\x64\SQLite.Interop.dll
  • %Program Files%\Lavasoft\Web Companion\Application\x86\SQLite.Interop.dll
  • %Program Files%\Lavasoft\Web Companion\Application\zh-CHS\WebCompanionInstaller.resources.dll
  • %Program Files%\Lavasoft\Web Companion\Application\zh-Hans\WebCompanion.resources.dll
  • %ProgramData%\Lavasoft\Web Companion\Options\Statistics.txt

Step 6

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.
  • %Program Files%\Lavasoft
  • %Program Files%\Lavasoft\Web Companion
  • %Program Files%\Lavasoft\Web Companion\Application
  • %Program Files%\Lavasoft\Web Companion\Application\de-DE
  • %Program Files%\Lavasoft\Web Companion\Application\en-US
  • %Program Files%\Lavasoft\Web Companion\Application\es-ES
  • %Program Files%\Lavasoft\Web Companion\Application\fr-CA
  • %Program Files%\Lavasoft\Web Companion\Application\it-IT
  • %Program Files%\Lavasoft\Web Companion\Application\ja-JP
  • %Program Files%\Lavasoft\Web Companion\Application\pt-BR
  • %Program Files%\Lavasoft\Web Companion\Application\ru-RU
  • %Program Files%\Lavasoft\Web Companion\Application\tr-TR
  • %Program Files%\Lavasoft\Web Companion\Application\x64
  • %Program Files%\Lavasoft\Web Companion\Application\x86
  • %Program Files%\Lavasoft\Web Companion\Application\zh-CHS
  • %Program Files%\Lavasoft\Web Companion\Application\zh-Hans
  • %ProgramData%\Lavasoft\
  • %ProgramData%\Lavasoft\Web Companion
  • %ProgramData%\Lavasoft\Web Companion\Options

Step 7

Disable this malware service

[ Learn More ]
    • WCAssistantService

Step 8

Scan your computer with your Trend Micro product to delete files detected as PUA.Win32.WebCompanion.BQ. 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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