Discovered: December 14, 2004
Updated: February 13, 2007 12:58:59 PM
Also Known As: Win32.Zafi.D [Computer Associa, Zafi.D [F-Secure], Email-Worm.Win32.Zafi.d [Kaspe, W32/Zafi.d@MM [McAfee], W32/Zafi.D.worm [Panda], W32/Zafi-D [Sophos], WORM_ZAFI.D [Trend Micro]
Type: Worm
Systems Affected: Windows


W32.Erkez.D@mm is a mass-mailing worm that sends itself to email addresses gathered from the infected computer. The worm may also attempt to lower security settings, terminate processes, and open a back door on the compromised computer.

Antivirus Protection Dates

  • Initial Rapid Release version December 14, 2004
  • Latest Rapid Release version August 08, 2016 revision 023
  • Initial Daily Certified version December 14, 2004
  • Latest Daily Certified version August 09, 2016 revision 001
  • Initial Weekly Certified release date December 14, 2004

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

Writeup By: John Canavan

Discovered: December 14, 2004
Updated: February 13, 2007 12:58:59 PM
Also Known As: Win32.Zafi.D [Computer Associa, Zafi.D [F-Secure], Email-Worm.Win32.Zafi.d [Kaspe, W32/Zafi.d@MM [McAfee], W32/Zafi.D.worm [Panda], W32/Zafi-D [Sophos], WORM_ZAFI.D [Trend Micro]
Type: Worm
Systems Affected: Windows


Once W32.Erkez.D@mm is executed, it performs the following actions:

  1. Creates the following files:

    • %System%\Norton Update.exe
    • C:\s.cm (A log file.)

      Note: %System% is a variable that refers to the System folder. By default, this is C:\Windows\System (Windows 95/98/Me), C:\Winnt\System32 (Windows NT/2000), or C:\Windows\System32 (Windows XP).

  2. Creates multiple copies of itself in the %System% folder as .dll files with eight-character, random file names.

  3. Attempts to create the following files in folders with the string "shar", "upload", or "music" in their name that it finds in the fixed drives C through H:

    • winamp 5.7 new!.exe
    • ICQ 2005a new!.exe


  4. Creates the following mutex named "Wxp4", so that only one copy of the worm is run on the infected computer.

  5. Adds the value:

    "Wxp4" = "%System%\Norton Update.exe"

    to the registry subkey:

    HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run

    so that the worm executes every time Windows starts.

  6. Creates the following registry subkey:

    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Wxp4

    where information about the worm is stored.

  7. Displays the following error message:

    Title: CRC: 04F7Bh
    Message: Error in packed file!

  8. Terminates processes with the following strings in their name:

    • reged
    • msconfig
    • task

  9. Attempts to connect to the microsoft.com domain.

  10. Opens a back door on TCP port 8181 and listens for commands from a remote attacker.

  11. Searches for .exe files in folders containing the following strings:

    • syman
    • viru
    • trend
    • secur
    • panda
    • cafee
    • sopho
    • kasper

      and attempts to terminate the processes for any of the executables found.

  12. Gathers email addresses from the infected computer and stores them in randomly named .dll files in the %System% folder.

  13. Retrieves email addresses from the Windows Address Book and from files with the following extensions:

    • .htm
    • .wab
    • .txt
    • .dbx
    • .tbb
    • .asp
    • .php
    • .sht
    • .adb
    • .mbx
    • .eml
    • .pmr
    • .fpt
    • .inb

      The worm avoids email addresses containing the following strings:

    • yaho
    • google
    • win
    • use
    • info
    • help
    • admi
    • ebm
    • micro
    • msn
    • hotm
    • suppor
    • syman
    • viru
    • trend
    • secur
    • panda
    • cafee
    • sopho
    • kasper

  14. Sends a copy of the worm to email addresses gathered from the computer, using its own SMTP engine.

    The email contains the following characteristics:

    From:
    (Spoofed)

    Subject:
    (One of the following)

    • Merry Christmas!
    • boldog karacsony...
    • Feliz Navidad!
    • ecard.ru
    • Christmas Kort!
    • Christmas Vykort!
    • Christmas Postkort!
    • Christmas postikorti!
    • Christmas - Kartki!
    • Weihnachten card.
    • Prettige Kerstdagen!
    • Christmas pohlednice
    • Joyeux Noel!
    • Buon Natale!

      Message:
      (One of the following)

    • Happy HollyDays!
      :) [Sender]
    • Kellemes Unnepeket!
      :) [Sender]
    • Feliz Navidad!
      :) [Sender]
    • :) [Sender]
    • Glaedelig Jul!
      :) [Sender]
    • God Jul!
      :) [Sender]
    • Iloista Joulua!
      :) [Sender]
      Naujieji Metai!
      :) [Sender]
    • Wesolych Swiat!
      :) [Sender]
    • Fröhliche Weihnachten!
      :) [Sender]
    • Prettige Kerstdagen!
      :) [Sender]
    • Veselé Vánoce!
      :) [Sender]
    • Joyeux Noel!
      :) [Sender]
    • Buon Natale!
      :) [Sender]


      Attachment: (Variable name with one of the following extensions)

    • .bat
    • .cmd
    • .com
    • .pif
    • .zip

      The following is an example of the email that the worm sent:



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.

Writeup By: John Canavan

Discovered: December 14, 2004
Updated: February 13, 2007 12:58:59 PM
Also Known As: Win32.Zafi.D [Computer Associa, Zafi.D [F-Secure], Email-Worm.Win32.Zafi.d [Kaspe, W32/Zafi.d@MM [McAfee], W32/Zafi.D.worm [Panda], W32/Zafi-D [Sophos], WORM_ZAFI.D [Trend Micro]
Type: Worm
Systems Affected: Windows


Removal using the W32.Erkez@mm Removal Tool
Symantec Security Response has developed a removal tool to clean the infections of W32.Erkez.D@mm. Use this removal tool first, as it is the easiest way to remove this threat.

Manual Removal
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. Restart the computer in Safe mode or VGA mode.
  4. Run a full system scan and delete all the files detected as W32.Erkez.D@mm.
  5. Reverse the changes made to the registry.
For details on each of these steps, read the following instructions.

1. To disable 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:
Note:
When you are completely finished with the removal procedure and are satisfied that the threat has been removed, re-enable System Restore by following the instructions in the aforementioned documents.

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. To update 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 daily. 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. To restart the computer in Safe mode or VGA mode

Shut down the computer and turn off the power. Wait for at least 30 seconds, and then restart the computer in Safe mode or VGA mode.
  • For Windows 95, 98, Me, 2000, or XP users, restart the computer in Safe mode. For instructions, read the document, "How to start the computer in Safe Mode."
  • For Windows NT 4 users, restart the computer in VGA mode.
4. To scan for and delete 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.Erkez.D@mm, click Delete.

5. To reverse the changes made to the registry

Important: 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 > Run.
  2. Type regedit

    Then click OK.

  3. Navigate to the key:

    HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run

  4. In the right pane, delete the value:

    "Wxp4" = "%System%\Norton Update.exe"

  5. Navigate to and delete the following key and its subkeys:

    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Wxp4

  6. Exit the Registry Editor.

  7. Restart the computer in Normal mode. For instructions, read the section on returning to Normal mode in the document, "How to start the computer in Safe Mode."


Writeup By: John Canavan