Alert level

Win32/Matcash


Encyclopedia entry
Updated: Aug 07, 2008  |  Published: Jul 29, 2008

Aliases
  • W32/Softomate (Norman)
  • Adware.Meplex (Sunbelt Software)
  • Trojan.Adclicker (Symantec)
  • Adware_Softomate (Trend Micro)
  • BrowserModifier:Win32/Matcash (other)

Alert Level (?)
High

Antimalware protection details
Microsoft recommends that you download the latest definitions to get protected.

Summary

Win32/Matcash is a multi-component family of trojans that downloads and executes arbitrary files. Some variants of this family may install a toolbar. The toolbar is installed as a Browser Helper Object (BHO), allowing the toolbar to run when the browser is launched. 

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Symptoms

System Changes
The following system changes may indicate the presence of Win32/Matcash:
  • Presence of the following registry key:
    Value: {9CA1A625-0AF0-1033-1027-050106270001}
    With data: update.exe
    In subkey: HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer\Run\
  • Presence of the following registry key values:
    HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Toolbar\WebBrowser
    HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Zoom
    HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer\Run\{9CA1A625-0AF0-1033-1027-050106270001}
    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Browser Helper Objects\{C004DEC2-2623-438e-9CA2-C9043AB28508}
  • Presence of the following files:
    <system folder>\bar888.dll
    <system folder>\speedtest2.dll
    <system folder>\svchosts.exe (not to be confused with svchost.exe, which resides in the same folder)
    <system folder>\tagrename_patch.exe
    <system folder>\unsvchosts.exe
    <system folder>\unsvchosts.lzma
    %temp%\nsw81.tmp\DetectionProcessus.dll
    %temp%\upd34.exe
    %CommonProgramFiles%\{3CA1A625-0AF0-1033-1027-050106270001}\888.dll
    %CommonProgramFiles%\{3CA1A625-0AF0-1033-1027-050106270001}\Uninstall.exe
    %CommonProgramFiles%\{9CA1A625-0AF0-1033-1027-050106270001}\Update.exe
    %CommonProgramFiles%\{9CA1A625-0AF0-1033-1027-050106270001}\system.dll

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Technical Information (Analysis)

Win32/Matcash is a multi-component family of trojans that downloads and executes arbitrary files. Some variants of this family may install a toolbar. The toolbar is installed as a Browser Helper Object (BHO), allowing the toolbar to run when the browser is launched. 
Installation
When Win32/Matcash is installed, it performs the following actions:
  • Drops a copy of the BHO toolbar as any of the following file names:
    <system folder>\bar888.dll
    <system folder>\speedtest2.dll
    <system folder>\svchosts.exe
    <system folder>\tagrename_patch.exe
    <system folder>\unsvchosts.exe
    <system folder>\unsvchosts.lzma
    %temp%\nsw81.tmp\DetectionProcessus.dll
    %temp%\upd34.exe
    %CommonProgramFiles%\{3CA1A625-0AF0-1033-1027-050106270001}\888.dll
    %CommonProgramFiles%\{3CA1A625-0AF0-1033-1027-050106270001}\Uninstall.exe
    %CommonProgramFiles%\{9CA1A625-0AF0-1033-1027-050106270001}\Update.exe
    %CommonProgramFiles%\{9CA1A625-0AF0-1033-1027-050106270001}\system.dll
  • Adds any of the following values to the registry to load the BHO whenever Internet Explorer is launched:
    HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Toolbar\WebBrowser
    HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Zoom
    HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer\Run\{9CA1A625-0AF0-1033-1027-050106270001}
    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Browser Helper Objects\{C004DEC2-2623-438e-9CA2-C9043AB28508}
Payload
Downloads and Executes Arbitrary Files
Trojan:Win32/Matcash connects to a remote Web site to download and execute arbitrary files. These files may include updates, additional components, or additional malware.

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Prevention

Take the following steps to help prevent infection on your system:
  • Enable a firewall on your computer.
  • Get the latest computer updates.
  • Use up-to-date antivirus software.
  • Use caution with attachments and file transfers.
Enable a firewall on your computer
Use a third-party firewall product or turn on the Microsoft Windows XP Internet Connection Firewall.
To turn on the Internet Connection Firewall in Windows XP
  1. Click Start, and click Control Panel.
  2. Click Network and Internet Connections. If you do not see Network and Internet Connections, click Switch to Category View.
  3. Click Change Windows Firewall Settings.
  4. Select On.
  5. Click OK.
To turn on the Windows Firewall in Windows Vista
  1. Click Start, and click Control Panel.
  2. Click Security.
  3. Click Turn Windows Firewall on or off.
  4. Select On.
  5. Click OK.
Get the latest computer updates
Updates help protect your computer from viruses, worms, and other threats as they are discovered. You can use the Automatic Updates feature in Windows XP to automatically download future Microsoft security updates while your computer is on and connected to the Internet.
To turn on Automatic Updates in Windows XP
  1. Click Start, and click Control Panel. 
  2. Click System.
  3. Click Automatic Updates.
  4. Select a setting. Microsoft recommends selecting Automatic. If you do not choose Automatic, but you choose to be notified when updates are ready, a notification balloon appears when new downloads are available to install. Click the notification balloon to review and install the updates.
Use up-to-date antivirus software
Most antivirus software can detect and prevent infection by known malicious software. To help protect you from infection, you should always run antivirus software that is updated with the latest signature files. Antivirus software is available from several sources. For more information, see http://www.microsoft.com/protect/computer/viruses/vista.mspx.
Use caution with attachments and file transfers
Exercise caution with e-mail and attachments received from unknown sources, or received unexpectedly from known sources.  Use extreme caution when accepting file transfers from known or unknown sources.

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Recovery

Win32/Matcash may place an uninstaller entry in 'Add or Remove Programs' in Control Panel. The entry name may be called '888Bar'. If an uninstaller is not available or if you do not want to use the uninstaller that is provided, use Microsoft Windows Defender or another up-to-date scanning and removal tool to detect and remove Win32/Matcash, or other potentially unwanted software from your computer.

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