Threat Explorer

The Threat Explorer is a comprehensive resource consumers can turn to for daily, accurate, up-to-date information on the latest threats, risks and vulnerabilities.

Adware.YinStart

Adware.YinStart

Updated:
February 13, 2007
Risk Impact:
High
File Names:
smss.exe
Systems Affected:
Windows

Behavior


Adware.YinStart modifies the Internet Explorer home page without your permission.

Symptoms


The Microsoft Internet Explorer start page is reset to www.1yin.com.

Antivirus Protection Dates

  • Initial Rapid Release version October 02, 2014 revision 022
  • Latest Rapid Release version October 02, 2014 revision 022
  • Initial Daily Certified version October 20, 2004
  • Latest Daily Certified version September 28, 2010 revision 036
  • Initial Weekly Certified release date October 20, 2004
Click here for a more detailed description of Rapid Release and Daily Certified virus definitions.

When Adware.YinStart runs, it does the following:

  1. Copies itself as %Windir%\smss.exe.

    Note: %Windir% is a variable that refers to the Windows installation folder. By default, this is C:\Windows or C:\Winnt.

  2. Adds the value:

    "smss.exe"="%Windir%\smss.exe"

    to the registry keys:

    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    HKEY_LOCAL_MACHINE\software\microsoft\windows\CurrentVersion\Runservices
    HKEY_CURRENT_USER\software\microsoft\windows\currentVersion\Run
    HKEY_CURRENT_USER\software\microsoft\windows\CurrentVersion\Runservices

    so that the adware runs when you start Windows.

  3. Adds the value:

    "Run"="%Windir%\smss.exe"

    to the registry key:

    HKEY_CURRENT_USER\software\microsoft\Windows NT\CurrentVersion\Windows

    so that the adware runs when you start Windows.

  4. Modifies the value:

    "Start Page"="http:/ /www.1yin.com"

    in the registry key:

    HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main

  5. May redirect browser to movie925.com.


The following instructions pertain to all Symantec antivirus products that support Security Risk detection.
  1. Update the definitions.
  2. Run a full system scan.
  3. Delete the value that was added to the registry.
  4. Reset the Internet Explorer home page.

For specific details on each of these steps, read the following instructions.

1. To update the definitions
To obtain the most recent definitions, start your Symantec program and run LiveUpdate.


2. To run the scan
  1. Start your Symantec antivirus program, and then run a full system scan.
  2. If any files are detected as Adware.YinStart and depending on which software version you are using, you may see one or more of the following options:

    Note: This applies only to versions of Norton AntiVirus that support Security Risk detection. If you are running a version of Symantec AntiVirus Corporate Edition that supports Security Risk detection, and Security Risk detection has been enabled, you will only see a message box that gives the results of the scan. If you have questions in this situation, contact your network administrator.
    • Exclude (Not recommended): If you click this button, it will set the threat so that it is no longer detectable. That is, the antivirus program will keep the security risk on your computer and will no longer detect it to remove from your computer.

    • Ignore or Skip: This option tells the scanner to ignore the threat for this scan only. It will be detected again the next time that you run a scan.

    • Cancel: This option is new to Norton Antivirus 2005. It is used when Norton Antivirus 2005 has determined that it cannot delete a security risk. This Cancel option tells the scanner to ignore the threat for this scan only, and thus, the threat will be detected again the next time that you run a scan.

      To actually delete the security risk:
      • Click its file name (under the Filename column).
      • In the Item Information box that displays, write down the full path and file name.
      • Then use Windows Explorer to locate and delete the file.

        If Windows reports that it cannot delete the file, this indicates that the file is in use. In this situation, complete the rest of the instructions on this page, restart the computer in Safe mode, and then delete the file using Windows Explorer.

    • Delete: This option will attempt to delete the detected files. In some cases, the scanner will not be able to do this.
      • If you see a message, "Delete Failed" (or similar message), manually delete the file.
      • Click the file name of the threat that is under the Filename column.
      • In the Item Information box that displays, write down the full path and file name.
      • Then use Windows Explorer to locate and delete the file.

        If Windows reports that it cannot delete the file, this indicates that the file is in use. In this situation, complete the rest of the instructions on this page, restart the computer in Safe mode, and then delete the file using Windows Explorer.


3. To delete the value from the registry

Important:
Symantec strongly recommends that you back up the registry before making any changes to it. Incorrect changes to the registry can result in permanent data loss or corrupted files. Modify the specified keys only. Read the document, "How to make a backup of the Windows registry ," for instructions.

  1. Click Start > Run.
  2. Type regedit

    Then click OK.

  3. Navigate to the key:

    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    HKEY_LOCAL_MACHINE\software\microsoft\windows\CurrentVersion\Runservices
    HKEY_CURRENT_USER\software\microsoft\windows\currentVersion\Run
    HKEY_CURRENT_USER\software\microsoft\windows\CurrentVersion\Runservices

  4. In the right pane, delete the value:

    "smss.exe"="%Windir%\smss.exe"

  5. Navigate to the key:

    HKEY_CURRENT_USER\software\microsoft\Windows NT\CurrentVersion\Windows

  6. In the right pane, delete the value:

    "Run"="%Windir%\smss.exe"

  7. Exit the Registry Editor.

4. To reset the Internet Explorer home page
  1. Start Microsoft Internet Explorer.

  2. Connect to the Internet, and then go to the page that you want to set as your home page.

  3. Click Tools > Internet Options.

  4. In the Home page section of the General tab, click Use Current > OK.

For additional information, or if this procedure does not work, read the Microsoft® Knowledge Base article, "Home Page Setting Changes Unexpectedly, or You Cannot Change Your Home Page Setting, Article ID 320159 ."