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Discovered: October 05, 2004
Updated: February 13, 2007 12:26:26 PM
Also Known As: Bloodhound.Packed, Bloodhound.W32.5, I-Worm.VB.q [Kaspersky], WORM_FILI.A [Trend Micro]
Type: Worm
Systems Affected: Windows

W32.Fili.A@mm is a generic Visual Basic worm that propagates via Microsoft Outlook and through peer-to-peer file-sharing networks. It can also spread via mIRC.

The email has a variable subject and attachment name. The attachment will have a .scr, .pif, .bat, .com, .cmd, or .exe file extension.


  • Virus definitions released prior to October 6, 2004 will detect this threat as Bloodhound.Packed or Bloodhound.W32.5.
  • Virus definitions released prior to October 11, 2004 will detect this threat as W32.Fili@mm.

Antivirus Protection Dates

  • Initial Rapid Release version October 06, 2004
  • Latest Rapid Release version September 28, 2010 revision 054
  • Initial Daily Certified version October 06, 2004
  • Latest Daily Certified version September 28, 2010 revision 036
  • Initial Weekly Certified release date October 06, 2004

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

Writeup By: Maryl Magee

Discovered: October 05, 2004
Updated: February 13, 2007 12:26:26 PM
Also Known As: Bloodhound.Packed, Bloodhound.W32.5, I-Worm.VB.q [Kaspersky], WORM_FILI.A [Trend Micro]
Type: Worm
Systems Affected: Windows

When W32.Fili.A@mm runs, it performs the following actions:

  1. Copies itself to %System%\pilif.exe.

    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. Adds the value:

    "Pilif" = "%System%\pilif.exe"

    to the registry key:


    so that the worm runs when Windows starts.

  3. Creates the following files:
    • %System%\adrbook
    • mIRC folder\Manifesto Anti Censore Pilif.txt.exe

  4. Searches for KaZaA, Morpheus, eDonkey, Grokster, limewire, ICQ, and WinMX-shared directories and copies itself as:
    • Norton 2004 crack
    • Kasperky AV Universal Key
    • Dark Coderz Alliance
    • Anti-hacker Utility
    • Cracks mega warez collection
    • Sex - totally free porn
    • Easy credit card validation
    • Yahoo hacker
    • Webmail official hacker
    • Free porn sites accounts

  5. Adds the value:

    "DisableTaskMgr" = "00000001"

    to the registry key:


    to disable the task manager.

  6. Sends itself as an email attachment to all the email addresses in the Microsoft Outlook address book. The email has the following characteristics:

    Subject: (one of the following)
    • Important legal notice!
    • Please help us to save the right of freedom of expression!
    • Please help us be free! We need the basic right of expression

      : (one of the following)
    • request
    • manifesto
    • pilif
    • sustain cause
    • details
    • attachement
    • Manifesto anti pilif
    • Manifesto details
    • Freedom of expression
    • Simple solution
    • Government issue

      With one of the following extensions:
    • .bat
    • .cmd
    • .com
    • .exe
    • .pif
    • .scr

      Body: (one of the following)
    • Do not delete this message. Analyse attachement and reply
      as soon as possible with manifesto details.
      Thank you!
    • All details will be displayed in small attached file. Good luck and
      thank you.
    • Its just hip-hop. Nothing else. Enjoy!
    • You personal manifesto details are attached. Take good care of them!
    • Help us gather online votes for our anti-censore manifesto

    • We need you help now! Attachement will automatically send a vote to our
      online database once you run it and will be redirected to our webpage!
    • Its curious, its scandalous... dont be so furious!
    • Life is bitch so dont take it serious.
    • Please help us be free! We need the basic right of expression.
    • Enable an online vote for our manifesto with the help of the attachement.
      Many thanks!
    • Music is beeing censored, journalists are afraid, law has not been
      respected for long time. Why? Because of corruption and lack of right of
      expression. Help us! Enable the attachement and our voting system will
      track and record you help. Many thanks!
    • Parazitii need your help for the anti-censore campaign! See all details
      in the attachement. Thank you!
    • Oh yeah! one more thing: its a censore-related manifesto :)
    • This is my manifesto. You can stop this individual,
      but you can't stop us all...after all,we're all alike.

  7. Searches the system for mirc or mirc32 and adds text to the file script.ini in order to send itself via IRC.

  8. Attempts to disable the following antivirus and security-related processes, if they are running:
    • Kaspersky Anti-Virus
    • Kaspersky AV Control Centre
    • Agnitium Firewall
    • Sygate Personal Firewall
    • Windows Updater
    • Zone Alarm
    • Kaspersky Anti-Virus Personal

  9. Runs a process with the same name as the copy of the worm, for example: pilif.exe

  10. Attempts to shut down and restart the infected computer by presenting the user with the shutdown menu.


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: Maryl Magee

Discovered: October 05, 2004
Updated: February 13, 2007 12:26:26 PM
Also Known As: Bloodhound.Packed, Bloodhound.W32.5, I-Worm.VB.q [Kaspersky], WORM_FILI.A [Trend Micro]
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.

Important: On computers running Norton AntiVirus 2005 or later, the QuickScan tool will automatically search for and remove malicious threats when new virus definitions are downloaded. While every effort has been made to ensure that the QuickScan tool removes all the traces of a malicious threat from an infected computer, we advise that you confirm that all the files and registry entries have been removed. We recommend following the manual removal steps and deleting any threat-related files or registry entries remaining on the computer.

  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.Fili.A@mm.
  4. Delete the value that was added to the registry.
For specific 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:

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 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.Fili.A@mm, click Delete.

    If your Symantec antivirus product reports that it cannot delete an infected file, Windows may be using the file. To fix this, run the scan in Safe mode. For instructions, read the document, "How to start the computer in Safe Mode." Once you have restarted in Safe mode, run the scan again.

    (After the files are deleted, you can leave the computer in Safe mode and proceed with section 4. When that is done, restart the computer in Normal mode.)

4. To delete the value from the registry

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:


  4. In the right pane, delete the value:

    "Pilif" = "%sysdir%\pilif.exe"

  5. Navigate to and reset the following registry key:


  6. Exit the Registry Editor.

Writeup By: Maryl Magee