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Discovered: June 04, 2003
Updated: February 13, 2007 12:02:01 PM
Also Known As: W32.HLLW.Xolox@mm
Type: Worm
Systems Affected: Windows

W32.HLLW.Lavits is a worm that attempts to spread across the KaZaA file-sharing network. This worm also uses Microsoft Outlook to send email to all the contacts in the Microsoft Outlook Address Book. When W32.HLLW.Lavits is run, it will display a fake message with the message title "Application Error."

The email does not have an attachment. The email messages have the following characteristics:

Subject: Where are you?
Message Body:
Where are you?,I enjoy speaking with you :)
Simdi icinden buda kim diyorsundur :)

W32.HLLW.Lavits is written in Visual Basic (VB) and is packed with UPX.

NOTE: Definitions dated prior to June 6, 2003 may detect this threat as W32.HLLW.Xolox@mm.

Security Response could not successfully reproduce the mass-mailing routine in a controlled laboratory environment. The worm did not attach itself to any outgoing emails.

Antivirus Protection Dates

  • Initial Rapid Release version June 05, 2003
  • Latest Rapid Release version September 28, 2010 revision 054
  • Initial Daily Certified version June 05, 2003
  • Latest Daily Certified version September 28, 2010 revision 036
  • Initial Weekly Certified release date June 05, 2003

Click here for a more detailed description of Rapid Release and Daily Certified virus definitions.

Writeup By: Scott Gettis

Discovered: June 04, 2003
Updated: February 13, 2007 12:02:01 PM
Also Known As: W32.HLLW.Xolox@mm
Type: Worm
Systems Affected: Windows

W32.HLLW.Lavits runs, it does the following:

  1. Display the fake message:

  2. Copies itself to the %Windir% folder as the following files:
    • Systemcheck.exe
    • Clean_insect.exe
    • Kiss.exe
    • Photo.jpg.exe
    • Unhappy.exe

      NOTE: %Windir% is a variable. The worm locates the Windows installation folder (by default, this is C:\Windows or C:\Winnt) and copies itself to that location.

  3. Copies itself as C:\Festival.exe.

  4. Adds the value:


    to the registry key:


  5. To replicate across the KaZaA file-sharing network, the worm copies itself as the following filenames:
    • Attack.exe
    • Php Hack.exe
    • DivX.exe
    • password.exe
    • Free mp3.exe
    • icq hack.exe
    • hotmail hack.exe
    • Linux Mandrakee.exe
    • Counter Strike Hack.exe
    • Linux.exe
    • Redhat.exe
    • Backdoor.exe
    • Linux Kernel Hacking.exe
    • Windows Keygen.exe
    • Windows XP.exe
    • WinXP keygen.exe
    • Half Life Cdkey.exe
    • Mail Hacking.exe
    • Mail Hack.exe
    • Free Shell Account.exe
    • Account Hacking.exe
    • Domain Hack.exe
    • Divx Mpeg.exe
    • Free Divx.exe
    • Norton Antivirus.exe
    • Kaspersky.exe
    • Security.exe
    • Office.exe
    • Ms Office XP Service Pack.exe
    • Share Hack.exe
    • Xp Service Pack 2.exe
    • Matrix.exe
    • Matrix Reloaded.exe
    • Underworld.exe
    • Gta.exe
    • ICQ.exe
    • Icq Password.exe
    • Der Schuh des Manitu.exe
    • Anger Management.exe
    • Computer Security.exe
    • Undelete.exe
    • Zip Password Recovery.exe
    • Antitrojan.exe
    • Office Password Recovery.exe
    • Hacker.exe
    • Firewall.exe
    • Linux Exploit.exe
    • Exploit.exe
    • Ptrace.exe
    • Ssh.exe
    • Linux Kernel Module.exe
    • Sniffer.exe
    • Cheat.exe
    • Windows 2000 Password Hack.exe
    • XP Password Crack.exe
    • Ftp Crack.exe
    • Ftp Password Crack.exe
    • Linux Worm.exe
    • Sqlsnake.exe
    • Hound.exe
    • r3x.exe
    • Divx Codec.exe
    • root password.exe
    • root hack.exe
    • Asp Hack.exe
    • Cgi Hack.exe
    • Raptor.exe
    • Brute Force.exe
    • All Games Cd-Key.exe
    • All Games Trainer.exe
    • Counter Strike Trainer.exe
    • Half Life Trainer.exe
    • All Games Hack.exe
    • Matrix Reloaded Trainer.exe
    • Matrix Cheat.exe
    • Fake Mailbomb.exe
    • Mailbomb.exe
    • DDoS.exe
    • Rootkit.exe
    • Port Scan.exe
    • Port Flood.exe
    • Port Hack.exe
    • Mysql.exe
    • Mysql Password Hack.exe
    • Domain Spoof.exe
    • Julia Roberts.exe
    • Firewall Hack.exe
    • Scanner.exe
    • Exploit Scan.exe
    • Sub7 Password Crack.exe
    • Subseven Hack.exe
    • Trojan Hack Center.exe
    • Modem Hack.exe
    • Unix Password Cracker.exe
    • DDoS Scan.exe
    • Linux Hack Attack.exe
    • Hack Lesson.exe
    • Linux Keylogger.exe
    • Keylogger.exe
    • Log Clean.exe
    • Apache Hack.exe
    • Telnet Hack.exe
    • MsSQL2000.exe
    • Irc Hack.exe
    • Irc Op Crack.exe
    • Nickserv Password.exe
    • Chanserv Password.exe
    • Free Bnc.exe
    • Anonmail.exe
    • Bot Hack.exe
    • Eggdrop Hack.exe
    • WebDav Hacking.exe
    • Netbios Hack.exe
    • Netbios Password Crack.exe
    • PwlTools.exe
    • Pwl Hack.exe
    • AIM Pass .exe
    • Aimcrack.exe
    • aimhacker.exe
    • AMI BIOS Cracker.exe
    • Award BIOS.exe
    • Yahoo Hack.exe
    • Messenger Hack.exe
    • Flood.exe
    • IP Hack.exe
    • Yahoo mail hack.exe
    • Trinity Dream.exe
    • Zion.exe
    • Matrix Zion.exe
    • How Hack.exe

      into these folders:
      • C:\KaZaA\My Shared Folder
      • C:\Program Files\KaZaA\My Shared Folder

  6. Sends email to all the addresses in the Outlook Address Book. The email does not have an attachment.
    This email message has the following characteristics:

    Subject: Where are you?

    Message Body:
    Where are you?,I enjoy speaking with you :)
    Simdi icinden buda kim diyorsundur :)

  7. To make Windows 95/98/Me computers run the worm each time you start Windows, the worm modifies the[windows] section of the C:\Windows\Win.ini file by adding the line:

    run= c:\Windows\Systemcheck.exe

  8. Drops and runs a VBS script named C:\Festival.vbs, which creates a script.ini file in the mIRC folder. The worm uses this script.ini file to spread via mIRC.

    These scripts are detected as VBS.Lavits.


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.

Writeup By: Scott Gettis

Discovered: June 04, 2003
Updated: February 13, 2007 12:02:01 PM
Also Known As: W32.HLLW.Xolox@mm
Type: Worm
Systems Affected: Windows

The following instructions pertain to all current and recent Symantec antivirus products, including the Symantec AntiVirus and Norton AntiVirus product lines.

  1. Disable System Restore (Windows Me/XP).
  2. Update the virus definitions.
  3. Run a full system scan and delete all the files detected as W32.HLLW.Lavits.
  4. Delete the value that was added to the registry.
  5. Edit the changes made to the Win.ini file (Windows 95/98/Me).
For specific details on each of these steps, read the following instructions.

1. Disabling System Restore (Windows Me/XP)
If you are running Windows Me or Windows XP, we recommend that you temporarily turn off System Restore. Windows Me/XP uses this feature, which is enabled by default, to restore the files on your computer in case they become damaged. If a virus, worm, or Trojan infects a computer, System Restore may back up the virus, worm, or Trojan on the computer.

Windows prevents outside programs, including antivirus programs, from modifying System Restore. Therefore, antivirus programs or tools cannot remove threats in the System Restore folder. As a result, System Restore has the potential of restoring an infected file on your computer, even after you have cleaned the infected files from all the other locations.

Also, a virus scan may detect a threat in the System Restore folder even though you have removed the threat.

For instructions on how to turn off System Restore, read your Windows documentation, or one of the following articles:
For additional information, and an alternative to disabling Windows Me System Restore, see the Microsoft Knowledge Base article, "Antivirus Tools Cannot Clean Infected Files in the _Restore Folder ," Article ID: Q263455.

2. 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: Read "How to update virus definition files using the Intelligent Updater" for detailed instructions.

3. 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 W32.HLLW.Lavits, click Delete.

4. Deleting the value from the registry

CAUTION : Symantec strongly recommends that you back up the registry before making 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:


  4. In the right pane, delete the value:


  5. Exit the Registry Editor.

5. Editing the Win.ini file
If you are running Windows 95/98/Me, follow these steps:
  1. The function you perform depends on your operating system:
    • Windows 95/98: Go to step b.
    • Windows Me: If you are running Windows Me, the Windows Me file-protection process may have made a backup copy of the Win.ini file that you need to edit. If this backup copy exists, it will be in the C:\Windows\Recent folder. Symantec recommends that you delete this file before continuing with the steps in this section. To do this:
      1. Start Windows Explorer.
      2. Browse to and select the C:\Windows\Recent folder.
      3. In the right pane, select the Win.ini file and delete it. The Win.ini file will be regenerated when you save your changes to it in step f.

  2. Click Start, and then click Run.
  3. Type the following, and then click OK.

    edit c:\windows\win.ini

    (The MS-DOS Editor opens.)

    NOTE: If Windows is installed in a different location, make the appropriate path substitution.

  4. In the [windows] section of the file, look for the line:

    run= c:\Windows\Systemcheck.exe

  5. Delete the line if it exists.
  6. Click File, and then click Save.
  7. Click File, and then click Exit.

Writeup By: Scott Gettis