VBS.Celeron.Worm

SUMMARY

The VBS.Celeron.Worm attempts to spread itself through the KaZaA file-sharing network. The existence of the file CELERON_VIVE.txt is an indication of a possible infection.

Protection

• Virus Definitions (LiveUpdate™ Weekly) December 24, 2002
• Virus Definitions (Intelligent Updater) December 24, 2002

Threat Assessment

Wild

• Wild Level: Low
• Number of Infections: 0 - 49
• Number of Sites: 0 - 2
• Geographical Distribution: Low
• Threat Containment: Easy
• Removal: Moderate

Damage

• Damage Level: Low
• Deletes Files: C:Autoexec.bat

Distribution

• Distribution Level: Medium
• Shared Drives: Copies itself to the KaZaA default shared folder

TECHNICAL DETAILS

When the VBS.Celeron.Worm runs, it does the following:

• Displays the fake message:

• Copies itself as the following files:
  
  • C:WindowsSystem32Ken32.vbs
  • C:WindowsSSystemScrip.txt.vbs
  • C:WindowsSPrueba.vbs
  • C:Program FilesKazaaMy Shared FolderCristina.jpg.vbs
  • C:Program FilesKazaaMy Shared FolderLesbianas.jpg.vbs
  • C:Program FilesKazaaMy Shared FolderSexo.jpg.vbs
  • C:Program FilesKazaaMy Shared FolderVideo porno.jpg.vbs
  • C:Program FilesKazaaMy Shared FolderAnal.jpg.vbs
  • C:Program FilesKazaaMy Shared FolderBritney.jpg.vbs

NOTE: These paths and filenames, including the double letter S in C:WindowsS, are hard-coded in the worm.

As a result, if you have KaZaA installed, other KaZaA users may download the worm files from your computer.

• Adds the values:

Run C:WINDOWSsystem32Ken32.vbs
Windll C:WINDOWSsystemScrip.txt.vbs

to the registry key

HKEY_LOCAL_MACHINESoftwareMicrosoftWindowsCurrentVersionRun

so that the worm runs when you restart Windows.

• Creates the following files:
  • C:Documents and SettingsOwnerDesktopCELERON_VIVE.txt
  • C:CELERON_VIVE.txt

These two files are both text files that contain the following text:
Celeron. DOLOMEDES 1.0
YO SOY UNA FORMA DE VIDA

NOTE: The aforementioned two files are not viral by themselves, and as such, Symantec antivirus products do not detect them.

• Deletes the file C:Autoexec.bat.

• Attempts to download and run the file Fotos.html from a predefined Web site, if the current system date is the 24th of the month.

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 are for all current and recent Symantec antivirus products, including the Symantec AntiVirus and Norton AntiVirus product lines. On Windows 95/98/Me systems, if the worm deleted the Autoexec.bat file, replace it from a clean backup.

1. Update the virus definitions.
2. Run a full system scan and delete all the files detected as the VBS.Celeron.Worm.
3. Delete the values
   
   Run C:WINDOWSsystem32Ken32.vbs
   Windll C:WINDOWSsystemScrip.txt.vbs
   
   from the registry key
   
   HKEY_LOCAL_MACHINESOFTWAREMicrosoftWindowsCurrentVersionRun
   

For further details, read the following instructions.

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, look at the Virus Definitions (LiveUpdate) line at the top of this writeup.
• 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, look at the Virus Definitions (Intelligent Updater) line at the top of this writeup.
  
  The Intelligent Updater virus definitions are available here. For detailed instructions on how to download and install the Intelligent Updater virus definitions from the Symantec Security Response Web site, click here.

Scanning for and repairing the infected files

1. Start your Symantec antivirus software 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.Celeron.Worm, click Delete.

Deleting the value from the registry

CAUTION: Symantec strongly recommends that you back up the registry before you make 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, then click Run. (The Run dialog box appears.)
2. Type regedit and then click OK. (The Registry Editor opens.)
3. Navigate to the key HKEY_LOCAL_MACHINESOFTWAREMicrosoftWindowsCurrentVersionRun.
   
4. In the right pane, delete the values:
   
   Run C:WINDOWSsystem32Ken32.vbs
   
   Windll C:WINDOWSsystemScrip.txt.vbs
   
5. Exit the Registry Editor.