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Discovered: February 20, 2002
Updated: February 13, 2007 11:52:52 AM
Also Known As: W32.Maldal.gen@mm
Type: Worm

W32.Maldal.I@mm is a mass-mailing worm that is written in Visual Basic. The worm attempts to send itself to all contacts in the Microsoft Outlook address book. It also creates several registry keys and files on the system.

NOTE: Definitions dated prior to February 21, 2002, may detect this threat as either Trojan Horse or W32.Maldal.gen@mm.

Antivirus Protection Dates

  • Initial Rapid Release version February 21, 2002
  • Latest Rapid Release version March 03, 2008 revision 035
  • Initial Daily Certified version February 21, 2002
  • Latest Daily Certified version March 03, 2008 revision 037
  • Initial Weekly Certified release date February 21, 2002

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

Writeup By: Andre Post

Discovered: February 20, 2002
Updated: February 13, 2007 11:52:52 AM
Also Known As: W32.Maldal.gen@mm
Type: Worm

When W32.Maldal.I@mm is executed, it does the following:

  1. First, it displays a black message box that contains red text. The text appears as follows:

    Sorry ! You are not registered .
    Please contact us :
    [Telephone numbers]

    Email :
    [Email addresses]

    To subscribe, send a blank message to :
    [Email address]

  2. Next, W32.Maldal.I@mm inserts the following files on the system:
    • %System%\ZaCker.pif
    • %Windows%\ZaCker.pif
    • %Windows%\Hide.pif

      • %Windows% is a variable. The worm locates the \Windows folder (by default this is C:\Windows or C:\Winnt) and copies itself to that location.
      • %Windows\System% is a variable. The worm locates the \Windows\System folder (by default this is C:\Windows\System or C:\Winnt\System32) and copies itself to that location.
  3. It inserts one .pif file into every folder on the hard drive, using that folder's name with the .pif extension. For example, in the \Windows folder, the inserted file would be named Windows.pif.

    All of the inserted files consist entirely of the worm itself.
  4. Next, it adds the following values:

    NAV DefAlert       %Windows%\ZaCker.pif
    Norton Auto-Protect       %Windows%\Hide.pif

    to the registry key


    NOTE: If the value NAV DefAlert already exists, the worm modifies it. This value is used by some versions of Norton AntiVirus. In either case, removing it as directed in the removal instructions does not affect the ability of Norton AntiVirus to run or detect viruses.
  5. Additionally, in this same registry key:


    the worm creates a value for every .pif file that it inserted on the system. The name of the value is equal to the folder that the .pif file was inserted in. For example, the %System%\System.pif file is added as follows:

    system       %System%\system.pif

    These registry modifications cause the worm to run when you start Windows.
  6. The worm also searches through .htm and .html files for email addresses to email itself to. So that it does not send email to itself, the worm takes the user's email address from the following registry keys:

    HKEY_USERS\.DEFAULT\Software\Microsoft\Internet Account Manager\Accounts\00000001\SMTP Email Address
    HKEY_USERS\.DEFAULT\Software\Microsoft\Office\Outlook\OMI Account Manager\Accounts\00000001\SMTP Email Address

    The email has the following characteristics:

    Subject: The subject line is randomly picked from one of the following:

    Fwd: Remember our survivors
    Fwd: The demand of sex ... where does it lead us to?
    Fwd: Say 'I Love You' in 300 languages
    Fwd: WoOoOoOow
    Fwd: Wow , We are the same!
    Fwd: [Muzicana - Group] Download what you want
    Zakia Zakaria & Najati :P
    Take a picture for yourself (Don't be mad it's only a joke)
    Fwd: Is there any true love?
    Fwd: Have u ever seen your face?! (Funny)
    Fwd: Against the power of women
    Fwd: Fwd: If you care about your wife
    Fwd: [*Offensive Language Removed*] OOOH Faster
    Fwd: Send it to everybody you love ;)
    Re: Fwd: Romantic Day
    Fwd: Let's Dance and forget pains
    Fwd: Loneliness
    Fwd: [sex-is] HoT MoVies
    Fwd: [SpanishGirlsGroup] Hola ...
    Fwd: [*Offensive Language Removed*-group] Lick my <Offensive Language Removed>
    Fwd: [Pussyland-egroup] How sweet
    Fwd: [DrFun-egroup] Let's Laugh
    Fwd: [FuNnY-egroup]Hehehehehe damn
    Fwd: [*Offensive Language Removed*-egroup] <Offensive Language Removed> girl
    Fwd: [Scr-News-egroup] Have you ever seen BLOOD
    Fwd: [Gays-egroup] Oh Shittttt
    Fwd: [Yabdoo-egroup] For HaCkers Lovers
    Fwd: [Jews-egroup] Sharon Owns The World
    Fwd: [FunMaiL-group] Bush under bin laden's <Offensive Language Removed>
    Fwd: [Teen-egroup] Three Ways For Love
    Fwd: [RomanticLife-group] Learn How To Love
    Fwd: [JewsFood-egroup] Dogs Meat !!!
    Fwd: [PianoMoZart-egroup] Wow Romantic
    Fwd: Tonight is... The Night Of Sex
    Fwd: Are you looking for FUN!!!?
    Fwd: [*Offensive Language Removed*-egroup] <Offensive Language Removed> On my face :O
    Fwd: [Finance-group] Do you wanna be a rich man?
    Fwd: Fwd: [lovedreams-egroup] love speaks from the heart
    Fwd: Change your life with Dr. Jobreee
    Fwd: [TerroNews-Group] Too Late... Bin Laden has been killed
    Fwd: [Pc.CLup-group] Learn how to deal with DOS
    Fwd: [*Offensive Language Removed*-eGroup] Oh My God !!!
    Fwd: The rights of women!!!

    Message: There is no body text in the email message.

    Attachment: This is a copy of the worm itself. The file is picked at random from any of the inserted files.
  7. After some time, the worm displays the following message in red on a black background:

    ZaCker Is N


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: Andre Post

Discovered: February 20, 2002
Updated: February 13, 2007 11:52:52 AM
Also Known As: W32.Maldal.gen@mm
Type: Worm

To remove this worm, delete files that are detected as Trojan Horse or W32.Maldal.I@mm, and remove the values that the worm added to the registry.

  1. Obtain the most recent virus definitions. There are two ways to do this:
    • Run LiveUpdate. LiveUpdate is the easiest way to obtain virus definitions. These virus definitions have undergone full quality assurance testing by Symantec Security Response and are posted to the LiveUpdate servers one time each week (usually Wednesdays) unless there is a major virus outbreak. To determine if definitions for this threat are available by LiveUpdate, look at the Virus Definitions (LiveUpdate) line at the top of this write-up.
    • Download the definitions using the Intelligent Updater. Intelligent Updater virus definitions have undergone full quality assurance testing by Symantec Security Response. They are posted on U.S. business days (Monday through Friday). They must be downloaded from the Symantec Security Response Web site and installed manually. To determine if definitions for this threat are available by the Intelligent Updater, look at the Virus Definitions (Intelligent Updater) line at the top of this write-up.

      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. Start Norton AntiVirus (NAV), and make sure that NAV is configured to scan all files. For instructions on how to do this, read the document How to configure Norton AntiVirus to scan all files.
  3. Run a full system scan.
  4. Delete all files that are detected as Trojan Horse or W32.Maldal.I@mm.

Also, revert all the registry changes that the worm made.

To edit the registry:

CAUTION : We strongly recommend 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 only the keys that are specified. Read the document How to back up the Windows registry for instructions.
  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:

  4. In the right pane, delete the following values:

    NAV DefAlert       %Windows%\ZaCker.pif
    Norton Auto-Protect       %Windows%\Hide.pif

    In addition, delete all values in which the file name that is referred to in the second column ends with the extension .pif. For example:

    system       %System%\system.pif
  5. Click Registry, and click Exit.

Writeup By: Andre Post