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.
When run, the worm creates the following registry key:
HKEY_CURRENT_USER\Software\OnTheFly
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_USER\Software\OnTheFly\mailed
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.
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.
Virus definitions dated February 12, 2001, or later will detect this worm. To remove VBS.SST@mm:
Run LiveUpdate to make sure that you have the most recent virus definitions.
Start Norton AntiVirus (NAV), and run a full system scan, making sure that NAV is set to scan all files.
If any files are detected as infected by VBS.SST@mm, click Delete
(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.
Click Start, and click Run. The Run dialog box appears.
Type regedit and then click OK. The Registry Editor opens.
Navigate to and delete the following key:
HKEY_CURRENT_USER\Software\OnTheFly
Exit the Registry Editor.
Additional information:
The following information is for network administrators of corporate versions of Norton AntiVirus.
For corporate users, Symantec Technical Support recommends the following
Make sure virus definitions are most current.
Delete the email. Do not open the attachment.
Disable Windows Scripting to prevent VBS files, such as AnnaKournikova.JPEG.VBS, from executing. Filter attachments with a VBS extension.
Microsoft Exchange 2000 in VAPI mode can strip attachments by extension. Contact Microsoft for further information.
Microsoft Exchange Server also provides the ExMerge utility, which can be used to purge the Information Store of messages with a specified subject or attachment name. This can be very useful during a virus crisis. For more information, please see the following Microsoft Articles:
Outlook 2000 with the latest security update will not execute VBS attachments. Contact Microsoft for further information.
Norton AntiVirus for Microsoft Exchange (NAVMSE) can block attachments by extension when in VAPI mode. Make sure NAVMSE is at a current build. The following Symantec's Knowledge Base documents may be helpful:
Norton AntiVirus for Email Gateways 2.0 installed, attachments with VBS extensions can be blocked. See the Administrator's Guide for details. The following Symantec Knowledge Base document may also be helpful:
Norton AntiVirus for Firewalls 1.5 installed, attachments with VBS extensions can sometimes be blocked. See the Administrator's Guide for details. There are unknown environmental factors that prevent some installations from blocking VBS files. If it works at your site, it will work reliably. If VBS blocking does not work at your site, it will not work at all.
Revision History:
September 20, 2002: Downgraded from Category 3 to Category 2 based on decreased rate of submissions.
