Threat Explorer

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29 December 2000
13 February 2007
Also Known As:

VBS.TQLL.A@mm is a worm that is written in Visual Basic Script. As of 6:00 P.M. PST on December 29, 2000, Symantec has had no confirmed reports
of this virus, and it is considered low risk at this time.

The worm is sent by email with the following subject, message, and attachment:

Subject:  New Year !

Message:  Wow Happy New Year !

Attachment:  happynewyear.txt.vbs

The attachment size is 10,390 bytes.

The worm will not execute by simply reading the email message. If the attached Happynewyear.txt.vbs file is executed, it creates a malicious program named 3k.exe in the \Windows folder. Happynewyear.txt.vbs will then run 3k.exe automatically. 3k.exe is a Trojan horse program. Norton AntiVirus will detect it as Backdoor.TQLL. The worm also sends itself to everyone in your Microsoft Outlook address book.

Some of the content of the VBS script is encrypted using simple encryption. Because of this, it is not possible to filter for this worm by looking for specific text within the VBS code.


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:
  1. Run LiveUpdate to make sure that you have the most recent definitions.
  2. Start Norton AntiVirus (NAV), and run a full system scan. Unless you are using Norton AntiVirus 2001, make sure that NAV is set to scan all files.
  3. Delete any files that are detected as infected by VBS.TQLL.A@mm or Backdoor.TQLL.

Writeup By: Motoaki Yamamura