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Discovered: March 12, 2004
Updated: February 13, 2007 12:19:00 PM
Type: Worm
Systems Affected: Windows

W32.HLLW.Annil@mm is a mass-mailing worm that uses its own SMTP engine to spread. The email subject, message, and attachment vary.

This threat also attempts to spread through the KaZaA file-shaing network.

Antivirus Protection Dates

  • Initial Rapid Release version March 13, 2004
  • Latest Rapid Release version September 28, 2010 revision 054
  • Initial Daily Certified version March 13, 2004
  • Latest Daily Certified version September 28, 2010 revision 036
  • Initial Weekly Certified release date March 13, 2004

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

Writeup By: Yana Liu

Discovered: March 12, 2004
Updated: February 13, 2007 12:19:00 PM
Type: Worm
Systems Affected: Windows

When W32.HLLW.Annil@mm runs, it does the following:

  1. Displays a fake message:

  2. Randomly selects a folder and copies itself to the folder using a randomly generated file name.

  3. Creates a subkey to,


    It uses the worm file name as the key name.
  4. Adds a value that refers to its copy to the registry key:


    so that the worm runs when you restart Windows.

    For example, the worm may copy itself as C:\Program Files\qfctgmt.exe, and then add the following value to the registry key:

    "qfctgmta"="C:\Program Files\qfctgmt.exe"

  5. Creates a registry key:


    and adds the following values to this key:

    "UpgradeEXE"="Hire Me"

  6. Set the values to:

    "Start Page"="http: //www.cnn.com"

    in the registry key:

    HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main

  7. Set the value to:


    in the registry key:


  8. Set the following values:


  9. Copies itself to the KaZaA shared folder. The file names are selected from the following:
    • hotstuff.scr
    • carmenelectra.scr
    • winzipcrack.exe
    • hl2source.com
    • doom2.exe
    • blueprints.scr
    • funnyscreensaver.scr
    • Opera7Beta.exe
    • Passion.scr
    • The last samuri-flash.scr
    • Cold Mountain-flash.scr
    • James Bond-flash.scr
    • Eminem Unleashed-flash.scr
    • SuperBowlJanet-flash.scr
    • Resident Evil 2-flash.scr
    • XboxHack.com
    • winzip32.exe
    • winXPcrack.exe
    • winzip32.com
    • Madonna-Video.exe
    • Warcraft3Beta.exe
    • desktopmate.exe
    • stripper.exe
    • AdobePhotoShopPlugin.com
    • AnarchistCookbook.scr
    • MatrixSaver.scr
    • Annil-RemoveTool.exe
    • Annihilator.exe
    • f16Sim.exe
    • CheatBook2003.scr

  10. Retrieves the computer user's email address from registry keys.

  11. Constructs the email addresses in the form <email_name@domain>, where email_name and domain may be selected from a list that the worm carries.

  12. Uses its own SMTP engine to send itself to the email addresses that it constructs.

    The email has the following characteristics:

    Subject: The subject is one of the following:
    • I finally finished my program!
    • Your request.
    • I've been hurt. But am alright.
    • Your beta test has arrived.
    • Hello!
    • Tommorow?
    • News!
    • Old classmate.
    • Klex virus making its rounds.
    • I found your password :)
    • Do you want this?
    • Postmaster: Message Failure
    • Postmaster: Undeliverable Mail
    • Postmaster: Message Failure
    • What is this?
    • : New billing procedure.
    • Incorrect Address...
    • Your dad.
    • Hilarous joke.
    • Your family.
    • Faked emode.com results.
    • Problem with %s...
    • I can't load %s...
    • %s is screwing up.
    • WTF is up with %s!!!
    • About %s
    • %s not working.
    • School tragedy!
    • Bomb!
    • School Policy!
    • Bomb threat!
    • School report.
    • School danger!.
    Message: The message is one of the following:
    • If you've been wondering why I haven't been staying in touch lately, it's because I've been working on a program in my spare time. I've finally got it to a testable state, and was wondering if you could give me feedback on it. Thanks in advance.
    • I hope you're the one who asked for this, I don't really remember, but thought I might as well send it anyway.
    • Well a lot of people haven't heard very much about my "injury", but my insurance company said I should give this to everybody I know. Run it and you'll understand everything.
    • Attention, Windows user:
    • We have detected a security gap within Windows internal dll's, we suggest all users run this program which seals the gap. Otherwise, any damaged data will not be compinsated for by Microsoft.
    • Sorry, I think I was supposed to send this earlier
    • Will this work for tommorow?
    • cool huh?
    • Ha. Remember this guy?
    • I'm typing this in a hurry, because I've got to go right away. But my computer was infected by the Klez virus, and I didn't realize it until a few days ago. You may have been infected as well. I apoligize!. This nifty little program fixes everything if you have in fact, been infected.
    • Hey, I managed to get your password for your e-mail. I suggest you use this utility (I attached it) to fortify your account and you can also use it to retrieve other peoples passwords (don't try it on me, since I already used it to protect mine). I'll keep my name secret, I don't want to get sued :) . BTW, I'm sending this to more people than just you, but I used it on multiple people.
    • Hey, I found this on Download.com a while ago and forgot to send it too you. I thought you may be interested. It should be attached, if it isn't just e-mail me again.
    • The following message could not be sent because the recipients mailbox was full.
    • Security Signature: 188X-08305-RETNMAIL
    • The following message could not be sent because the recipients mailbox was no longer available.
    • Security Signature: 165X-08605-RETNMAIL
    • The following message could not be sent because the recipients mailbox was full.
    • Security Signature: 165X-08605-UNDLVRMAIL
    • Can you tell me what this is?
    • We have started a new billing procedure, see the attached invoice for more information.
    • This message must have been sent to me by mistake, appearantly it's meant for you. Don't worry I didn't read all of it :).
    • Your dad told me to send this to you, i think you'll understand.
    • I thought you might enjoy this. Birds are so funny.
    • Outlook:Secure text document attached.
    • I got this from my dad's old attorney, he said it could be very useful to you.
    • I did a search for your name and I think someone faked your emode.com test results. See what you think:
    • Results automatically attached.
    • Everytime I type the address it keeps redirecting me to this file.
    • I can't seem to get the site working, it always sends me to a URL with this file. What's wrong?
    • Sorry to bother you, but when I try to load the site it always gives me this file.
    • Everytime I try to load the site I get sent this file.
    • Is there any way to keep it from sending me this file? Thanks.
    • Keeps dloading this.
    • I have good reasoning! See the image quickly!
    • Evidence!
    • Why do you let the kids play this awful game?
    • The bomb threat you may get today might be real, see the image:
    • Someone wants me to report this without giving names.
    • This demands immediate attention.
    Attachment: The attachment is one of the following:
    • MFCApp.exe
    • file.scr
    • BlueS-Injury.scr
    • MSSecure.scr
    • underdog
    • dogs.scr
    • gettogether.scr
    • Invoice.scr
    • yourmsg.scr
    • will.scr
    • joke.scr
    • billing
    • results
    with .scr as an extension.
    • KlezRem
    • PWordGet-Lite
    • SnowBall
    with either .bat, com, .exe, or .pif as an extension.

    • <random>
    • return
    • define

    with either .bat, .com, or .scr as an extension.

    • msupdate.exe
    • screenshot.scr
    • ie6upg.exe
    • flash6.com
    • apache.exe
    • index.scr
    • unknownurl.pif
    • autoupdate.exe
    • oddfile.exe
    • cgibin.com
    • qk193.zip.exe
    • servrequest.com

    with either .bat, .com, .exe, or .scr as an second extension.

    • guns.scr
    • powder.scr
    • doom
    • bomb.scr
    • violence.pif
    • shooting.com
    with either .bat, .com, or .exe as an second extension.

    It may also send its zip archive as an attachment.


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: Yana Liu

Discovered: March 12, 2004
Updated: February 13, 2007 12:19:00 PM
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. Restart the computer in Safe mode or VGA mode.
  4. Run a full system scan and delete all the files detected as W32.HLLW.Annil@mm.
  5. Delete the values that were added to the registry.
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:
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. 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. Restarting 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. 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.Annil@mm, click Delete.

5. Deleting the value from the registry

WARNING: 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. Type, or copy and paste, the following text into the file repair.reg:



  1. Run repair.reg.

  2. Click Start, and then click Run. (The Run dialog box appears.)

  3. Type regedit

    Then click OK. (The Registry Editor opens.)

  4. Navigate to the key:


  5. In the right pane, delete any value that refers to the worm file.

  6. Exit the Registry Editor.

Writeup By: Yana Liu