This program delivers advertising content to the user. It is usually annoying but harmless, unless it is combined with spyware or trackware.

Automatic action

Based on the settings of your F-Secure security product, it may block the file from running, move it to the quarantine where it cannot spread or cause harm, or ask you to select an action.

Suspect a file is incorrectly detected (a False Positive)?

A False Positive is when a file is incorrectly detected as harmful, usually because its code or behavior resembles known harmful programs. A False Positive will usually be fixed in a subsequent database update without any action needed on your part. If you wish, you may also:

  • Check for the latest database updates

    First check if your F-Secure security program is using the latest detection database updates, then try scanning the file again.

  • Submit a sample

    After checking, if you still believe the file is incorrectly detected, you can submit a sample of it for re-analysis.

    NOTE If the file was moved to quarantine, you need to collect the file from quarantine before you can submit it.

  • Exclude a file from further scanning

    If you are certain that the file is safe and want to continue using it, you can exclude it from further scanning by the F-Secure security product.

    Note You need administrative rights to change the settings.

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Technical Details

Adware:W32/Bestofer is one of the progams associated with "The Best Offer Networks" online advertising. When active, Bestofer contacts one of the "Best Offer Networks" servers to retrieve advertising content to display.&

Here's a sample screenshot of the adware information when it is installed:

Bestofer is distributed bundled together with several freeware applications.

Another adware that is related to this program is Adware:W32/BetterInternet.


During installation, the following files are created:

  • %windir%\tboninst.cfg
  • %windir%\TBONUnst.htm
  • %ProgramFiles%\tboninst.cfg
  • %ProgramFiles%\tbon.exe
  • %ProgramFiles%\Uninstall.exe

Where %WINDIR% refers to the Windows folder and the default installationpath is "C:\windows" (Windows 95/98/Me/XP) or "C:\Winnt" (Windows NT/2000). %ProgramFiles% refers to the program files directory and the default installation path is "c:\Program Files".


During installation, the following registry keys are created:

  • HKEY_CURRENT_USER\Software\tbonac
  • HKEY_CURRENT_USER\Software\Classes\tbonac
  • HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Uinstall\TBON
  • HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run& tbon = [adware file]