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VBS.Postcard@mm

VBS.Postcard@mm

Discovered:
08 March 2001
Updated:
13 February 2007

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, \Windows\System, 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.

Antivirus Protection Dates

  • Initial Rapid Release version 09 March 2001
  • Latest Rapid Release version 28 September 2010 revision 054
  • Initial Daily Certified version 09 March 2001
  • Latest Daily Certified version 28 September 2010 revision 036
  • Initial Weekly Certified release date pending
Click here for a more detailed description of Rapid Release and Daily Certified virus definitions.

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_MACHINE\Software\Microsoft\
    Windows\CurrentVersion\RegisteredOwner

    to

    Lord YuP - [C]apsule [C]orp

    and the value of

    HKEY_LOCAL_MACHINE\Software\Microsoft\
    Windows\CurrentVersion\RegisteredOrganization

    to

    DragonBall GT
  5. Next, it infects all files that have the extensions .html, .htm, .shtml, or .asp and are in the \Windows, \Windows\System, 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":

  • Use a firewall to block all incoming connections from the Internet to services that should not be publicly available. By default, you should deny all incoming connections and only allow services you explicitly want to offer to the outside world.
  • 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.
  • Ensure that programs and users of the computer use the lowest level of privileges necessary to complete a task. When prompted for a root or UAC password, ensure that the program asking for administration-level access is a legitimate application.
  • Disable AutoPlay to prevent the automatic launching of executable files on network and removable drives, and disconnect the drives when not required. If write access is not required, enable read-only mode if the option is available.
  • Turn off file sharing if not needed. If file sharing is required, use ACLs and password protection to limit access. Disable anonymous access to shared folders. Grant access only to user accounts with strong passwords to folders that must be shared.
  • Turn off and remove unnecessary services. By default, many operating systems install auxiliary services that are not critical. These services are avenues of attack. If they are removed, threats have less avenues of attack.
  • If a 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.
  • Configure your email server to block or remove email that contains file attachments that are commonly used to spread threats, such as .vbs, .bat, .exe, .pif and .scr files.
  • Isolate compromised computers quickly to prevent threats from spreading further. 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.
  • If Bluetooth is not required for mobile devices, it should be turned off. If you require its use, ensure that the device's visibility is set to "Hidden" so that it cannot be scanned by other Bluetooth devices. If device pairing must be used, ensure that all devices are set to "Unauthorized", requiring authorization for each connection request. Do not accept applications that are unsigned or sent from unknown sources.
  • For further information on the terms used in this document, please refer to the Security Response glossary.

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_MACHINE\Software\Microsoft\
    Windows\CurrentVersion\
  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.


Writeup By: Serghei Sevcenco