VBS.Postcard@mm

SUMMARY

This virus is a polymorphic Visual Basic Script (VBS), which is stored in HTML files or as a separate VBS file. It is both an email worm and a Trojan horse. When executed, the worm emails itself to everyone in your Microsoft Outlook address book. It infects files in the Windows, WindowsSystem, and Temp folders that have .html, .htm, .shtml, or .asp extensions

It also replicates itself to Temp folders of mapped network drives. The virus changes Internet Explorer security settings, and changes the default start page to the infected HTML page. It opens WordPad and enters text on the opened document. The script is also designed to block the keyboard and the mouse.

Protection

• Virus Definitions (Intelligent Updater) March 9, 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

Distribution

• Distribution Level: Low

TECHNICAL DETAILS

This virus is a polymorphic Visual Basic Script (VBS), which is stored in HTML files or as a separate VBS file. If the Security Settings of Internet Explorer are set correctly, then every time the infected HTML page is opened, the browser warns that some software on the page might be unsafe, with the recommendation to not run it. If you follow the recommendation, then the virus displays the following message:

To see a postcard you must apply the ActiveX format

and returns control to the Internet Explorer warning message again. The loop continues until you allow the software to run. The only way to terminate the loop is to use Task Manager.

When executed, the Script performs the following actions:

1. It enables the following Internet Explorer Security setting for the local computer zone: "Initialize and script ActiveX controls not marked as safe." This zone is not listed on the Security tab of Internet Options. It allows the running of any scripts contained in HTML pages that are stored on a local computer without any permission prompts, just like separately stored scripts.
2. The virus replicates itself to the following files:
   • <Windows Folder> 2001.{3050F3D9-98B5-11CF-BB82-00AA00BDCE0B}
   • <System Folder> dragonball.GT(dan kokoro hikareteku).{3050F3D9-98B5-11CF-BB82-00AA00BDCE0B}
   • <Temp Folder> millenium.{3050F3D9-98B5-11CF-BB82-00AA00BDCE0B}
     This replication is set up as the Internet start page.
   • <Temp Folder> <random number, e.g. 0.6786267>post-card.tif.{3050F3D9-98B5-11CF-BB82-00AA00BDCE0B}
     This is used as an attachment in the next step. (The extension {3050F3D9-98B5-11CF-BB82-00AA00BDCE0B} is the class identifier (CLSID) of the MHTML (MIME Encapsulation of Aggregate HTML Documents) files. So, the replicated files will be displayed without an extension, and with an assigned icon similar to the following:
     
     
     
3. The script then drops and executes the <Windows Folder>[db.GT].wsf file. This file is a VBS email worm. When executed, it attaches the replicated file to a new message, and sends it out to everyone in your Microsoft Outlook address book.
   • The subject is one of the following:
     • Happy new Millenium (read the postcard (attached file))
     • Postcard for you is waiting (in attachment)
     • Happy 2001 (for more action check attached file)
     • Stroke of luck? in 2001? (happy 2001 -read attachment)
     • Goodies
     • You have got a postcard (attached file)
     • Someone sent you a postcard (in attachment)
       
   • The message body is in HTML format, and includes the following text:
     
     HaPPy NeW Millenium
     Happy new year
     Best wishes from:
     your dear ...
     
4. The Script next changes the value of
   
   HKEY_LOCAL_MACHINESoftwareMicrosoft
   WindowsCurrentVersionRegisteredOwner
   
   to
   
   Lord YuP - [C]apsule [C]orp
   
   and the value of
   
   HKEY_LOCAL_MACHINESoftwareMicrosoft
   WindowsCurrentVersionRegisteredOrganization
   
   to
   
   DragonBall GT
   
5. Next, it infects all files that have the extensions .html, .htm, .shtml, or .asp and are in the Windows, WindowsSystem, or Temp folders.
6. It then tries to replicate itself to the Temp folder of all mapped network drives as
   
   <Mapped Drive Letter>:docs.{3050F3D9-98B5-11CF-BB82-00AA00BDCE0B}
   
7. Next, the Script drops and runs the following VBScript:
   
   <Windows Folder>payl0ad.vbe
   
8. If it is Monday, 4:32, 4:37, or 4:38 (A.M. or P.M.), or if it is Thursday, 2:40 to 2:45 P.M., or 4:40 to 4:45 A.M., then the Payl0ad.vbe file is executed. This opens WordPad and enters the following text:
   
   DB FaMiLy sTrIkEz oNe MoRe Time wiTh:
   DB.GT  today we infected you but tommorow we will infect rest of the ANIME WORLD.
   YuP [C]apsule[C]orp
   
9. It also attempts to disable the keyboard and the mouse.

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 this worm, delete any files detected as VBS.Postcard, and then undo the changes to the registry.

To delete 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.Postcard.
   

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_MACHINESoftwareMicrosoft
   WindowsCurrentVersion
   
4. In the right pane, locate and double-click the following value:
   
   RegisteredOwner
   
5. In the Value Data box. replace the text that was added by the worm with the name of the registered owner of your copy of Windows, and then click OK.
6. In the right pane, locate and double-click the following value:
   
   RegisteredOrganization
   
7. In the Value Data box. replace the text that was added by the worm with the name of the registered organization for your copy of Windows, and then click OK. (If there is none, just delete the text.)
8. Close the Registry Editor.