VBS.Chunxiao@mm

SUMMARY

VBS.Chunxiao@mm is a Visual Basic Script worm. Like many other worms, it uses Microsoft Outlook to spread.

Protection

• Virus Definitions (Intelligent Updater) March 22, 2001

Threat Assessment

Wild

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

Damage

• Damage Level: Low
• Large Scale E-mailing: Send email to all contacts in the Outlook address book.

Distribution

• Distribution Level: High
• Subject of Email: ｧﾚｪｺ・ｨﾆ!!
• Name of Attachment: Xiaochun.TXT.vbs

TECHNICAL DETAILS

When the worm is run:

1. It copies itself to the following locations:
   • C:WindowsPccnt.vbs
   • C:WindowsSystemNavapw32.vbs
   • C:WindowsSystemXiaochun.txt.vbs
2. It sends an email message to all members of your Outlook Express address book. The email message, which is displayed in Chinese characters, has the following characteristics:
   • Subject: My Story!
   • Message: I would like to tell you a thing happed on me. It is really horrible. I steps a shit today.
   • Attachment: Xiaochun.TXT.vbs
3. It modifies the registry key
   
   HKEY_LOCAL_MACHINESoftwareMicrosoft
   WindowsCurrentVersionRun
   
   and adds the following entry:
   
   Norton Auto-Protect       <Windows System Folder>Navapw32.vbs    
   
4. It modifies the registry key
   
   HKEY_LOCAL_MACHINESoftwareMicrosoftWindowsCurrentVersionRunServices
   
   and adds the following entry:
   
   Trend OfficeScan        <Windows Folder>Pccnt.vbs
   

NOTE: The registry changes cause the worm to run when the computer starts.

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

To remove the worm, delete files detected as VBS.Chunxiao@mm and undo the changes it made to the registry.

To remove the worm:

1. Run LiveUpdate to make sure that you have the most recent virus definitions.
2. Start Norton AntiVirus (NAV), and run a full system scan, making sure that NAV is set to scan all files.
3. Delete any files detected as VBS.Chunxiao@mm.

To edit the registry:

CAUTION: We strongly recommend that you back up the system registry before making any changes. Incorrect changes to the registry could result in permanent data loss or corrupted files. Please make sure you modify only the keys specified. Please see the document How to back up the Windows registry before proceeding.

1. Click Start, and click Run. The Run dialog box appears.
2. Type regedit and then click OK. The Registry Editor opens.
3. Navigate to the following key:
   
   HKEY_LOCAL_MACHINESoftwareMicrosoftWindowsCurrentVersionRun
   
4. In the right pane, delete the following value:
   
   Norton Auto-Protect       <Windows System Folder>Navapw32.vbs
   
5. Navigate to the following key:
   
   HKEY_LOCAL_MACHINESoftwareMicrosoftWindowsCurrentVersionRunServices
   
6. In the right pane, delete the following value:
   
   Trend OfficeScan        <Windows Folder>Pccnt.vbs
   
7. Click Registry, and click Exit to save the changes.