Threat Explorer

The Threat Explorer is a comprehensive resource consumers can turn to for daily, accurate, up-to-date information on the latest threats, risks and vulnerabilities.

VBS.Ztin

VBS.Ztin

Discovered:
11 March 2003
Updated:
13 February 2007
Systems Affected:
Windows

VBS.Ztin is a VBS script that attempts to spread using various peer-to-peer programs. VBS.Ztin may also overwrite .jpg and .jpeg files. The payload of this VBS script includes pinging certain URLs with large packets.



Additional precautions
VBS.Ztin, as well as other threats, use the VBScript computer language to run. You can protect yourself from threats that use this language by enabling Script Blocking (part of Norton AntiVirus 2002/2003 and is available for 2001) or by disabling or uninstalling the Windows Scripting Host. Because the Windows Scripting Host is an optional part of Windows, it can be safely removed from your computer. (However, some programs need this feature installed to properly function.)
  • If you are using any Symantec Enterprise product, such as Symantec AntiVirus Corporate Edition (SAVCE), contact your system administrator for additional information before you disable or uninstall the Scripting Host.
  • If you are using Norton AntiVirus 2002/2003, which includes Script Blocking, make sure that Script Blocking is enabled (the default). This protects you from malicious scripts, making it unnecessary to disable or uninstall the Scripting Host.
  • If you are using Norton AntiVirus 2001, a free program update that includes Script Blocking is available. Run LiveUpdate to obtain this. This protects you from malicious scripts, making it unnecessary to disable or uninstall the Scripting Host.
  • For older versions of Norton AntiVirus, Symantec Security Response offers a tool to disable the Windows Scripting Host.
  • To disable the Windows Scripting Host in Microsoft Outlook Express only, see the Microsoft Knowledge Base document, "OLEXP: How to Disable Active Scripting in Outlook Express," Article ID: Q192846.


Antivirus Protection Dates

  • Initial Rapid Release version 11 March 2003
  • Latest Rapid Release version 28 September 2010 revision 054
  • Initial Daily Certified version 11 March 2003
  • Latest Daily Certified version 28 September 2010 revision 036
  • Initial Weekly Certified release date 12 March 2003
Click here for a more detailed description of Rapid Release and Daily Certified virus definitions.

When VBS.Ztin is executed, it performs the following actions:
  1. Creates the following copies of itself:
    • C:\Windows\MS Script Tool.vbs
    • C:\Program Files\Kazaa\Kazaa_Search_Engine.vbs
    • C:\Program Files\KMD\My Shared Folder\Hot_Sluts.jpg.vbs
    • C:\Program Files\KMD\My Shared Folder\WinXp Key Gen.exe.vbs
    • C:\Program Files\KMD\My Shared Folder\Ozzy - Crazy Train.mp3.vbs
    • C:\Program Files\Kazaa\My Shared Folder\Hot_Sluts2.jpg.vbs
    • C:\Program Files\Kazaa\My Shared Folder\Norton's Serial Gen.exe.vbs
    • C:\Program Files\Kazaa\My Shared Folder\Good Charlotte - underGRADS Theme.mp3.vbs
    • C:\Program Files\KaZaA Lite\My Shared Folder\Hot_Sluts3.jpg.vbs
    • C:\Program Files\KaZaA Lite\My Shared Folder\Pc-Cillin2003 Crack.exe.vbs
    • C:\Program Files\KaZaA Lite\My Shared Folder\GreenDay - Paradise.mp3.vbs
    • C:\Program Files\Grokster\My Grokster\sexy_legs_redhead.jpg.vbs
    • C:\Program Files\Grokster\My Grokster\TrojanCleaner.exe.vbs
    • C:\Program Files\Grokster\My Grokster\Shakira - Whenever.mp3.vbs
    • C:\Program Files\BearShare\Shared\osama.jpg.vbs
    • C:\Program Files\BearShare\Shared\F-Secure Crack.exe.vbs
    • C:\Program Files\BearShare\Shared\Southpark - Eric Holy Nite.mp3.vbs
    • C:\Program Files\Edonkey2000\Incoming\terrorist.jpg.vbs
    • C:\Program Files\Edonkey2000\Incoming\Kazaa.exe.vbs
    • C:\Program Files\Edonkey2000\Incoming\Nelly - Hot In Here Remixed.mp3.vbs

  2. If the file, C:\Program Files\Kazaa\Kazaa_Search_Engine.vbs, was sucessfully created, the worm adds the value:

    KazaaP2P C:\Program Files\Kazaa\Kazaa_Search_Engine.vbs

    to the registry key:

    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
  3. Overwrites all .jpg and .jpeg files in the following folders with a copy of the worm:
    • C:\Program Files\KMD\My Shared Folder
    • C:\Program Files\Kazaa\My Shared Folder
    • C:\Program Files\KaZaA Lite\My Shared Folder
    • C:\Program Files\Grokster\My Grokster
    • C:\Program Files\BearShare\Shared
    • C:\Program Files\Edonkey2000\Incoming

      The overwritten file will have the original file name with the .vbs extension added to it.

  4. Searched for .mp3 or .mp2 files in the same folders mentioned in step 3. For each located file, the worm makes a copy of itself using the same file name, but with the .vbs extension. This means that the original .mp3 and .mp2 files are not overwritten.
  5. If the date is any of the following of any year:
    • February 17
    • March 1
    • March 15
    • April 1
    • June 1

      the worm will display a message and ping various Web sites with large ping packets.


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.

The following instructions pertain to all current and recent Symantec antivirus products, including the Symantec AntiVirus and Norton AntiVirus product lines.
  1. Update the virus definitions.
  2. Run a full system scan and delete all the files detected as VBS.Ztin.
  3. Delete the value that the worm added to the registry.
For specific details on each of these steps, read the following instructions.

1. Updating the virus definitions
Symantec Security Response fully tests all the virus definitions for quality assurance before they are posted to our servers. There are two ways to obtain the most recent virus definitions:
  • Running LiveUpdate, which is the easiest way to obtain virus definitions: These virus definitions are posted to the LiveUpdate servers once each week (usually on Wednesdays), unless there is a major virus outbreak. To determine whether definitions for this threat are available by LiveUpdate, refer to the Virus Definitions (LiveUpdate).
  • Downloading the definitions using the Intelligent Updater: The Intelligent Updater virus definitions are posted on U.S. business days (Monday through Friday). You should download the definitions from the Symantec Security Response Web site and manually install them. To determine whether definitions for this threat are available by the Intelligent Updater, refer to the Virus Definitions (Intelligent Updater).

    The Intelligent Updater virus definitions are available here. For detailed instructions on how to download and install the Intelligent Updater virus definitions from the Symantec Security Response Web site, click here.

2. Scanning for and deleting the infected files
  1. Start your Symantec antivirus program and make sure that it is configured to scan all the files.
  2. Run a full system scan.
  3. If any files are detected as infected with VBS.Ztin, click Delete.

3. Deleting the value from the registry

CAUTION : Symantec strongly recommends that you back up the registry before you make any changes to it. Incorrect changes to the registry can result in permanent data loss or corrupted files. Modify the specified keys only. Read the document, "How to make a backup of the Windows registry ," for instructions.
  1. Click Start, and then click Run. (The Run dialog box appears.)
  2. Type regedit

    Then click OK. (The Registry Editor opens.)
  3. Navigate to the key:

    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
  4. In the right pane, delete the value: KazaaP2P
  5. Exit the Registry Editor.


Writeup By: Neal Hindocha