VBS.HPWG.gen

SUMMARY

VBS.HPWG.gen is a worm that infects file-sharing networks. The known variants spread through KaZaA, Morpheus, Grokster, and Bearshare, but do not do any damage.

Protection

• Virus Definitions (LiveUpdate™ Weekly) March 25, 2003
• Virus Definitions (Intelligent Updater) March 21, 2003

TECHNICAL DETAILS

VBS.HPWG.gen worms are generated by a tool that allows the creator of the worm to configure details, such as filenames, which file-sharing networks to infect, and which method to use for automatic startup. This type of worm may do any or all of the following:

1. Copies itself to the %Windir% or %System% folder, using the same filename as the infected script.
   
   NOTES:
   • %Windir% is a variable. The worm locates the Windows installation folder (by default, this is C:Windows or C:Winnt) and copies itself to that location.
   • %System% is a variable. The worm locates the System folder and copies itself to that location. By default, this is C:WindowsSystem (Windows 95/98/Me), C:WinntSystem32 (Windows NT/2000), or C:WindowsSystem32 (Windows XP).
     
     
2. Adds the lines:
   
   @Echo Off
   Start <filename>.vbs
   
   to the C:Autoexec.bat file, so that the worm runs when you start Windows 95/98/Me.
   
   
3. Adds the value:
   
   "<anything>" = "%Windir%<filename>.vbs"
   
   to one the registry keys:
   
   HKEY_LOCAL_MACHINESoftwareMicrosoftWindowsCurrentVersionRun
   
   or:
   
   HKEY_CURRENT_USERSoftwareMicrosoftWindowsCurrentVersionRun
   
   
4. Displays a fake error message.
   
   
5. Copies itself to one or all of the following folders:
   
   • KaZaAMy Shared Folder
   • GroksterMy Grokster
   • MorpheusMy Shared Folder
   • BearshareShared
     
     NOTES:
     • These folders are located in the default Program Files folder. For example, C:Program FilesGroksterMy Grokster.
     • The filenames vary, but are often pornographic in nature and always have a .vbs extension.

Recommendations

Symantec Security Response encourages all users and administrators to adhere to the following basic security "best practices":

• Turn off and remove unneeded services. By default, many operating systems install auxiliary services that are not critical, such as an FTP server, telnet, and a Web server. These services are avenues of attack. If they are removed, blended threats have less avenues of attack and you have fewer services to maintain through patch updates.
• If a blended threat exploits one or more network services, disable, or block access to, those services until a patch is applied.
• Always keep your patch levels up-to-date, especially on computers that host public services and are accessible through the firewall, such as HTTP, FTP, mail, and DNS services (for example, all Windows-based computers should have the current Service Pack installed.). Additionally, please apply any security updates that are mentioned in this writeup, in trusted Security Bulletins, or on vendor Web sites.
• Enforce a password policy. Complex passwords make it difficult to crack password files on compromised computers. This helps to prevent or limit damage when a computer is compromised.
• Configure your email server to block or remove email that contains file attachments that are commonly used to spread viruses, such as .vbs, .bat, .exe, .pif and .scr files.
• Isolate infected computers quickly to prevent further compromising your organization. Perform a forensic analysis and restore the computers using trusted media.
• Train employees not to open attachments unless they are expecting them. Also, do not execute software that is downloaded from the Internet unless it has been scanned for viruses. Simply visiting a compromised Web site can cause infection if certain browser vulnerabilities are not patched.

REMOVAL

The following instructions pertain to all current and recent Symantec antivirus products, including the Symantec AntiVirus and Norton AntiVirus product lines.

1. Update the virus definitions.
2. Run a full system scan and delete all the files detected as VBS.HPWG.gen.
3. Remove the lines added to the Autoexec.bat file. (Windows 95/98/Me).
4. Delete the value that was added to the registry.

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

1. Updating the virus definitions

Symantec Security Response fully tests all the virus definitions for quality assurance before they are posted to our servers. There are two ways to obtain the most recent virus definitions:

• Running LiveUpdate, which is the easiest way to obtain virus definitions: These virus definitions are posted to the LiveUpdate servers once each week (usually on Wednesdays), unless there is a major virus outbreak. To determine whether definitions for this threat are available by LiveUpdate, refer to the Virus Definitions (LiveUpdate).
• Downloading the definitions using the Intelligent Updater: The Intelligent Updater virus definitions are posted on U.S. business days (Monday through Friday). You should download the definitions from the Symantec Security Response Web site and manually install them. To determine whether definitions for this threat are available by the Intelligent Updater, refer to the Virus Definitions (Intelligent Updater).
  
  The Intelligent Updater virus definitions are available: Read "How to update virus definition files using the Intelligent Updater" for detailed instructions.

2. Scanning for and deleting the infected files

1. Start your Symantec antivirus program and make sure that it is configured to scan all the files.
   • For Norton AntiVirus consumer products: Read the document, "How to configure Norton AntiVirus to scan all files."
   • For Symantec AntiVirus Enterprise products: Read the document, "How to verify that a Symantec Corporate antivirus product is set to scan all files."
2. Run a full system scan.
3. If any files are detected as infected with VBS.HPWG.gen, note the filename, and then click Delete.

3. Removing the lines from the Autoexec.bat file
If you run Windows 95/98/Me, follow these steps:

1. Click Start, and then click Run.
2. Type the following:
   
   edit c:autoexec.bat
   
   and then click OK. (The MS-DOS Editor opens.)
   
   
3. Delete any lines similar to the following, if found.:
   
   @Echo Off
   Start <file name>.vbs
   
   NOTE: The exact path and filename may vary.
   
   
4. Click File, and then click Save.
   
   
5. Click File, and then click Exit.
   
   

4. Deleting the value from the registry

CAUTION: 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, and then click Run. (The Run dialog box appears.)
2. Type regedit
   
   Then click OK. (The Registry Editor opens.)
   
   
3. Navigate to each of the keys:
   
   HKEY_LOCAL_MACHINESOFTWAREMicrosoftWindowsCurrentVersionRun
   
   and:
   
   HKEY_CURRENT_USERSOFTWAREMicrosoftWindowsCurrentVersionRun
   
   
4. In the right pane, delete any value which refers to the filenames that the worm uses. For instance:
   
   "<anything>"="%Windir%<filename>.exe.vbs"
   
   NOTE: The exact path and filename will vary.
   
   
5. Exit the Registry Editor.