WORM_YAHLOVER.JH

To identify and delete the malware/grayware file:

• On Windows XP and Server 2003 systems:

1. Scan your computer with your Trend Micro product and then take note of the names of the malware/grayware files detected.
2. Click Start>Run. In the Open input box, type secpol.msc and press Enter.
3. In the left panel, double-click Local Policies>Security Options.
4. In the right panel, double-click Recovery Console: Allow floppy copy and access to all drives and folders.
5. Select Enabled and click OK.
6. Insert the Windows Installation CD into the CD drive, then restart your computer.
7. When prompted, press any key to boot from the CD.
8. On the main menu, type r to go to the Recovery Console.
9. Type the number that corresponds to the drive and directory that contains Windows (usually C:\WINDOWS) and press Enter.
10. Type the Administrator password and press Enter.
11. In the input box, type the following then press Enter:
    SET AllowAllPaths = TRUE
    del "{malware/grayware path and file name}"
12. Type exit and press Enter to restart the system normally.

• On Windows Vista and 7 systems:

1. Scan your computer with your Trend Micro product and then take note of the names of the malware/grayware files detected.
2. Insert your Windows Installation DVD in the DVD drive, then Press the restart button.
3. When prompted, press any key to boot from the CD.
4. Depending on your Windows Installation DVD, you might be required to select the installation language. Then on the Install Windows window, choose your language, locale, and keyboard layout or input method. Click Next, then click Repair your computer.
5. Select Use recovery tools that can help fix problems starting Windows. Select your installation of Windows. Click Next.
6. If the Startup Repair window appears, click Cancel, Yes, then Finish.
7. In the System Recovery Options window, click Command Prompt.
8. In the Command Prompt window, type the following then press Enter:
   BootRec.exe /fixmbr
   del "{malware/grayware path and file name}"
9. Type exit and press Enter to close the Command Prompt window.
10. Click Restart to restart the system normally.

To delete the registry key this malware/grayware created:

1. Open Registry Editor. Click Start>Run, type REGEDIT, then press Enter.
2. In the left panel, double-click the following:
   HKEY_LOCAL_MACHINE>Software>Policies>Microsoft>Internet Explorer
3. Still in the left panel, locate and delete the key:
   Control Panel
4. In the left panel, double-click the following:
   HKEY_CURRENT_USER>Software>Policies>Microsoft>Internet Explorer
5. Still in the left panel, locate and delete the key:
   Control Panel
6. In the left panel, double-click the following:
   HKEY_LOCAL_MACHINE>SOFTWARE>Microsoft>Internet Explorer
7. Still in the left panel, locate and delete the key:
   SearchScopes
8. In the left panel, double-click the following:
   HKEY_CURRENT_USER>SOFTWARE>Microsoft>Internet Explorer
9. Still in the left panel, locate and delete the key:
   SearchScopes
10. Close Registry Editor.

To delete the registry value this malware/grayware created:

1. Open Registry Editor. Click Start>Run, type REGEDIT, then press Enter.
2. In the left panel, double-click the following:
   HKEY_CURRENT_USER>Software>Microsoft>Windows>CurrentVersion>Run
3. In the right panel, locate and delete the entry:
   Yahoo Messengger = "%System%\chrome9.exe"
4. In the left panel, double-click the following:
   HKEY_LOCAL_MACHINE>SOFTWARE>Policies>Microsoft>Internet Explorer>Control Panel
5. In the right panel, locate and delete the entry:
   HomePage = "1"
6. In the left panel, double-click the following:
   HKEY_CURRENT_USER>Software>Policies>Microsoft>Internet Explorer>Control Panel
7. In the right panel, locate and delete the entry:
   HomePage = "1"
8. In the left panel, double-click the following:
   HKEY_CURRENT_USER>Software>Microsoft>Internet Explorer>Main
9. In the right panel, locate and delete the entry:
   RunOnceComplete = "1"
10. In the left panel, double-click the following:
    HKEY_LOCAL_MACHINE>SOFTWARE>Microsoft>Internet Explorer>Main
11. In the right panel, locate and delete the entry:
    RunOnceComplete = "1"
12. Again In the right panel, locate and delete the entry:
    RunOnceHasShown = "1"
13. Again In the right panel, locate and delete the entry:
    RunOnceHasShown = "1"
14. In the left panel, double-click the following:
    HKEY_CURRENT_USER>Software>Microsoft>Search Assistant
15. In the right panel, locate and delete the entry:
    DefaultSearchURL = "http://www.{BLOCKED}l.co.uk/index.php?page
16. In the left panel, double-click the following:
    HKEY_CURRENT_USER>Software>Microsoft>Windows>CurrentVersion>Explorer>WorkgroupCrawler>Shares
17. In the right panel, locate and delete the entry:
    shared = "\New Folder.exe"
18. In the left panel, double-click the following:
    HKEY_LOCAL_MACHINE>SOFTWARE>Microsoft>Internet Explorer>SearchScopes
19. In the right panel, locate and delete the entry:
    URL = "{random characters}"
20. In the left panel, double-click the following:
    HKEY_CURRENT_USER>Software>Microsoft>Internet Explorer>SearchScopes
21. In the right panel, locate and delete the entry:
    URL = "{random characters}"
22. Close Registry Editor.

To restore registry values this malware/grayware modified:

1. Open Registry Editor. To do this:
   
   • On Windows 2000, XP, and Server 2003:
     Click Start>Run, type REGEDIT in the text box provided, and then press Enter.
   • On Windows Vista and 7:
     Click the Start button, type REGEDIT in the Search input field then press Enter.
2. In the left panel, double-click the following:
   HKEY_LOCAL_MACHINE>SOFTWARE>Microsoft>Internet Explorer>Main
3. In the right panel, locate the registry value:
   Default_Page_URL = "http://www.{BLOCKED}10.com"
4. Right-click on the value name and choose Modify. Change the value data of this entry to:
   Default_Page_URL = "http://www.microsoft.com/isapi/redir.dll?prd
5. Again In the right panel, locate the registry value:
   Default_Search_URL = "http://www.{BLOCKED}10.com"
6. Right-click on the value name and choose Modify. Change the value data of this entry to:
   Default_Search_URL = "http://www.microsoft.com/isapi/redir.dll?prd
7. Again In the right panel, locate the registry value:
   Search Page = "http://www.{BLOCKED}10.com"
8. Right-click on the value name and choose Modify. Change the value data of this entry to:
   Search Page = "http://www.microsoft.com/isapi/redir.dll?prd
9. Again In the right panel, locate the registry value:
   Start Page = "http://www.{BLOCKED}10.com"
10. Right-click on the value name and choose Modify. Change the value data of this entry to:
    Start Page = "http://www.microsoft.com/isapi/redir.dll?prd
11. In the left panel, double-click the following:
    HKEY_CURRENT_USER>Software>Microsoft>Internet Explorer>Main
12. In the right panel, locate the registry value:
    Start Page = "http://www.{BLOCKED}10.com"
13. Right-click on the value name and choose Modify. Change the value data of this entry to:
    Start Page = "http://www.microsoft.com/isapi/redir.dll?prd
14. In the left panel, double-click the following:
    HKEY_LOCAL_MACHINE>SOFTWARE>Microsoft>Windows NT>CurrentVersion>Winlogon
15. In the right panel, locate the registry value:
    Shell = "Explorer.exe chrome9.exe"
16. Right-click on the value name and choose Modify. Change the value data of this entry to:
    Shell = "Explorer.exe"
17. Close Registry Editor.

To manually delete a malware/grayware component from an affected system:

• For Windows 2000, Windows XP, and Windows Server 2003:

1. Right-click Start then click Search....
2. In the Named input box, type:
   
   • %Desktop%\Search.lnk
   • %Favorites%\Sioril.lnk
   • %User Startup%\Search bar.lnk
   • %User Profile%\My Documents\Search bar.lnk
   • %User Profile%\Quick Launch\Search.lnk
   • d:\New Folder.exe
   • d:\chrome9.exe
3. In the Look In drop-down list, select My Computer then press Enter.
4. Once located, select the file then press SHIFT+DELETE to delete it.
5. Repeat the said steps for all files listed.

• For Windows Vista and Windows 7 users:

1. Click Start>Computer.
2. In the Search input box, type:
   
   • %Desktop%\Search.lnk
   • %Favorites%\Sioril.lnk
   • %User Startup%\Search bar.lnk
   • %User Profile%\My Documents\Search bar.lnk
   • %User Profile%\Quick Launch\Search.lnk
   • d:\New Folder.exe
   • d:\chrome9.exe
3. Once located, select the file then press SHIFT+DELETE to delete it.
4. Repeat the said steps for all files listed.
   *Note: Read the following Microsoft page if these steps do not work on Windows 7.