W32.HLLW.Epon@mm

SUMMARY

W32.HLLW.Epon@mm is a worm that attempts to spread through file-sharing networks and mIRC. It also uses Microsoft Outlook to send itself to all the contacts in the Outlook address book.

The email has the following characteristics:

Subject: Britney Spears poses nude in the Playboy!
Attachment: Britney Spears.jpg<many spaces>.exe

The worm is written in Microsoft Visual C++ and is packed with UPX.

Protection

• Virus Definitions (LiveUpdate™ Weekly) December 3, 2003
• Virus Definitions (Intelligent Updater) December 3, 2003

Threat Assessment

Wild

• Wild Level: Low
• Number of Infections: 0 - 49
• Number of Sites: 0 - 2
• Geographical Distribution: Low
• Threat Containment: Easy
• Removal: Moderate

Damage

• Damage Level: Medium
• Payload Trigger: N/A
• Payload: N/A
• Large Scale E-mailing: Send itself to all the contacts in the Outlook Address Book.
• Deletes Files: Deletes C:IO.SYS, C:MSDOS.SYS, C:CONFIG.SYS, C:oot.ini
• Modifies Files: N/A
• Releases Confidential Info: N/A
• Degrades Performance: N/A
• Causes System Instability: N/A
• Compromises Security Settings: N/A

Distribution

• Distribution Level: High
• Subject of Email: Britney Spears poses nude in the Playboy!
• Name of Attachment: Britney Spears.jpg.exe
• Size of Attachment: 26,112 bytes
• Ports: N/A
• Shared Drives: N/A
• Target of Infection: Spreads itself through file-sharing networks, such as eDonkey2000, Grokster, KaZaA, Morpheus, Overnet, iMesh, and IRC as well.
• Time Stamp of Attachment: N/A

TECHNICAL DETAILS

When W32.HLLW.Epon@mm is executed, it performs the following actions:

1. Copies itself as %System%krnl32.exe.
   
   

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   Note: %System% is a variable. The worm locates the System folder and copies itself to that location. By default, this is C:WindowsSystem (Windows 95/98/Me), C:WinntSystem32 (Windows NT/2000), or C:WindowsSystem32 (Windows XP).

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2. Adds a value:
   
   "Kernel32"="%System%krnl32.exe"
   
   to the registry key:
   
   HKEY_LOCAL_MACHINESOFTWAREMicrosoftWindowsCurrentVersionRun
   
   so that the worm runs when Windows starts.
   
   
3. Creates a hidden folder, %System%Epyon, and may copy itself as the following:
   
   • Britney Spears.jpg<a series of blank spaces>.exe
   • Windows Longhorn (Beta Version).exe
   • Norton Anti-Virus 2004 Professional.exe
   • Anna Kournikova Screensaver (HOT!).scr
   • 15 yr old masturbating (hidden cam).avi<a series of blank spaces>.exe
   • HOW TO write viruses.pif
   • Free XXX passwords.pif
   • me fucking my sweet ex-girlfriend (she is so HOT!!).mpg<a series of blank spaces>.exe
   • Teen gangbang.avi<a series of blank spaces>.exe
   • Blonde in short skirt fucking (upskirt).mpg<a series of blank spaces>.exe
   • Drunk girl fucked by 3 guys (awsome!).mpg<a series of blank spaces>.exe
   • Estella Warren Screensaver (Hottest babe ever!).scr
   • Jennifer Lopez Screensaver.scr
   • Sarah Michelle Gellar Screensaver.scr
   • Buffy The Vampire Slayer Screensaver.scr
   • Grand Theft Auto Vice City - Multiplayer patch.exe
   • Quake IV (Beta but working!).exe
   • Unreal II - The Awakening Serail Generator.exe
   • Lord of the Rings - The Return of the King.exe
   • Need For Speed Underground.exe
   • The Fast and the Furious.exe
   • The Matrix Online.exe
   • Unreal Tournament 2004 (Full Game).exe
   • Final Fanatasy XII (English version).exe
   • Counter-Strike Condition Zero (Full working Game!).exe
   • Half Life 2 (Full Game).exe
     
     

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     Note: %System% is a variable. The worm locates the System folder and copies itself to that location. By default, this is C:WindowsSystem (Windows 95/98/Me), C:WinntSystem32 (Windows NT/2000), or C:WindowsSystem32 (Windows XP).

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4. Shares the %System%Epyon folder with the following file-sharing networks:
   
   • Morpheus
   • eDonkey2000
   • Overnet
   • iMesh
   • Grokster
   • KaZaA
     
     
5. Displays the message box:
   
   
   
   
   
6. Deletes the following files:
   
   • C:IO.SYS
   • C:MSDOS.SYS
   • C:CONFIG.SYS
   • C:oot.ini
     
     
7. Drops and executes a Visual Basic Script named %Windir%TempEpyon.vbs. This script uses Microsoft Outlook to send itself to all the contacts in the Outlook address book. The email has the following characteristics:
   
   Subject: Britney Spears poses nude in the Playboy!
   Attachment: Britney Spears.jpg<many spaces>.exe
   
   
8. Drops an mIRC script file named C:script.ini. The worm uses this to spread via mIRC as the file, mIRC Update.exe.

Recommendations

Symantec Security Response encourages all users and administrators to adhere to the following basic security "best practices":

• Turn off and remove unneeded services. By default, many operating systems install auxiliary services that are not critical, such as an FTP server, telnet, and a Web server. These services are avenues of attack. If they are removed, blended threats have less avenues of attack and you have fewer services to maintain through patch updates.
• If a blended 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 (for example, all Windows-based computers should have the current Service Pack installed.). Additionally, please apply any security updates that are mentioned in this writeup, in trusted Security Bulletins, or on vendor Web sites.
• 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.
• Configure your email server to block or remove email that contains file attachments that are commonly used to spread viruses, such as .vbs, .bat, .exe, .pif and .scr files.
• Isolate infected computers quickly to prevent further compromising your organization. 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.

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. Run a full system scan and delete all the files detected as W32.HLLW.Epon@mm.
4. Delete the value 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:

• "How to disable or enable Windows Me System Restore"
• "How to turn off or turn on Windows XP System Restore"

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

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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.
   • For Norton AntiVirus consumer products: Read the document, "How to configure Norton AntiVirus to scan all files."
   • For Symantec AntiVirus Enterprise products: Read the document, "How to verify that a Symantec Corporate antivirus product is set to scan all files."
2. Run a full system scan.
3. If any files are detected as infected with W32.HLLW.Epon@mm, click Delete.

4. Deleting the value from the registry

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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.

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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:
   
   HKEY_LOCAL_MACHINESOFTWAREMicrosoftWindowsCurrentVersionRun
   
   
4. In the right pane, delete the value:
   
   "Kernel32"="%Sysdir%krnl32.exe"
   
   
5. Exit the Registry Editor.