VBS.SST@mm

SUMMARY

VBS.SST@mm is a VBS email worm that has been encoded using a virus creation kit. This worm arrives as an attachment named AnnaKournikova.jpg.vbs. When executed, the worm emails itself to everyone in your Microsoft Outlook address book. On January 26, the worm will attempt to direct your Web browser to an Internet address in The Netherlands, from where the worm appears to have originated.

Behavior

Symptoms

Transmission

Protection

• Virus Definitions (LiveUpdate™ Weekly) February 12, 2001
• Virus Definitions (Intelligent Updater) February 12, 2001

Threat Assessment

Wild

• Wild Level: Low
• Number of Infections: More than 1000
• Number of Sites: More than 10
• Geographical Distribution: High
• Threat Containment: Easy
• Removal: Moderate

Damage

• Damage Level: Low
• Payload Trigger: January 26
• Payload: Directs Web browser to http://www.dynabyte.nl

Distribution

• Distribution Level: High
• Subject of Email: Here you have, ;o)
• Name of Attachment: AnnaKournikova.jpg.vbs
• Size of Attachment: 2853

TECHNICAL DETAILS

When run, the worm creates the following registry key:

HKEY_CURRENT_USERSoftwareOnTheFly

If the worm is run on January 26, it attempts to direct your Web browser to an Internet address in The Netherlands.

Next, it checks to see if the mass-mailing routine has been executed. If not, the worm emails everyone in your Microsoft Outlook address book and sets the following key value equal to "1" (this is equivalent to true):

HKEY_CURRENT_USERSoftwareOnTheFlymailed

This prevents the mail routine from running again.

The subject, body and attachment sent by the worm are as follows:

Subject:

Here you have, ;o)

Message body:

Hi:
Check This!

Attachment:

AnnaKournikova.jpg.vbs

The worm continues running, and if it is deleted, it attempts to recreate itself. Due to a bug in the code, the worm instead recreates itself as a zero-byte file.

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

Virus definitions dated February 12, 2001, or later will detect this worm. To remove VBS.SST@mm:

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. If any files are detected as infected by VBS.SST@mm, click Delete
4. (Optional -- This is not necessary for the function of your system.) Delete the registry key that was added by the worm.
   

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 and delete the following key:
   
   HKEY_CURRENT_USERSoftwareOnTheFly
   
4. Exit the Registry Editor.