The following instructions have been created to help you to get rid of "Win32.Webdir.b" manually.
Use this guide at your own risk; software should usually be better suited to remove malware, since it is able to look deeper.

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Threat Details:

Categories:
  • trojan

Description:
Win32.Webdir.b installs real components of sound and video codecs into the Windows and system directories. Also copies and registers a malicious VirtualDNS.dll into the Windows directory without giving the user a possibility to cancel that process.
Removal Instructions:

Files:

Please use Windows Explorer or another file manager of your choice to locate and delete these files.
  • The file at "<$WINDIR>\VirtualDNS.dll".
Make sure you set your file manager to display hidden and system files. If Win32.Webdir.b uses rootkit technologies, use our RootAlyzer or our Total Commander anti-rootkit plugins.
You will have to use a global search for files without a name specified. Be extra careful, because just the name might not be enough to identify files!

Important: There are more files that cannot be safely described in simple words. Please use Spybot-S&D to remove them.

Folders:

Please use Windows Explorer or another file manager of your choice to locate and delete these folders.
  • The directory at "<$PROGRAMS>\AVI Codec Pack ".
  • The directory at "<$PROGRAMFILES>\AVI Codec Pack".
  • The directory at "<$PROGRAMFILES>\AVI Codec Pack\AC3".
  • The directory at "<$PROGRAMFILES>\AVI Codec Pack\LAYER-3".
Make sure you set your file manager to display hidden and system files. If Win32.Webdir.b uses rootkit technologies, use our RootAlyzer or our Total Commander anti-rootkit plugins.
You will have to use a global search for files without a name specified. Be extra careful, because just the name might not be enough to identify folders!

Important: There are more files that cannot be safely described in simple words. Please use Spybot-S&D to remove them.

Registry:

You can use regedit.exe (included in Windows) to locate and delete these registry entries.
  • Delete the registry key "VirtualDNS.DLL" at "HKEY_CLASSES_ROOT\AppID\".
  • Delete the registry key "{86C510E9-97EF-4749-914F-0280247BE3A6}" at "HKEY_CLASSES_ROOT\CLSID\".
  • Delete the registry key "{1F63B171-E2F3-4362-A484-8563144D62E6}" at "HKEY_CLASSES_ROOT\Interface\".
  • Delete the registry key "{143414D1-C324-4D6F-9756-5075D9A4A485}" at "HKEY_CLASSES_ROOT\TypeLib\".
  • A key in HKEY_CLASSES_ROOT\ named "VirtualDNS.VirtualDNSObj", plus associated values.
  • A key in HKEY_CLASSES_ROOT\ named "VirtualDNS.VirtualDNSObj.1", plus associated values.
  • Delete the registry key "{86C510E9-97EF-4749-914F-0280247BE3A6}" at "HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Browser Helper Objects\".
  • Delete the registry key "AVI Codec Pack" at "HKEY_LOCAL_MACHINE\SOFTWARE\".
If Win32.Webdir.b uses rootkit technologies, use our RegAlyzer, RootAlyzer or our Total Commander anti-rootkit plugins.

Final Words:

If neither Spybot-S&D nor self help did resolve the issue or you would prefer one on one help,
  1. Please read these instructions before requesting assistance,
  2. Then start your own thread in the Malware Removal Forum where a volunteer analyst will advise you as soon as available.