W32.HLLW.Erife@mm

SUMMARY

W32.HLLW.Erife@mm is a mass-mailing, network-aware worm. It retrieves email addresses from the Microsoft Outlook address book and a variety of file types, then uses Outlook, or the current MAPI program, to spread itself. It also modifies script.ini to spread through mIRC.

The email has one of the following characteristics:

Subject: %emailname%,How Are You?
Attachment: My-Cool-Screen-Save.Scr

Subject: This Mail For My %emailname%!
Attachment: Well-Computer-Game.Exe

Subject: %emailname%,Help Me!
Attachment: Photo.Jpg.Scr

Subject: Sex Movie For My %emailname%!
Attachment: Sex-Movie.Exe

This threat is written in the Microsoft Visual Basic programming language.

Protection

• Virus Definitions (LiveUpdate™ Weekly) October 1, 2003
• Virus Definitions (Intelligent Updater) September 26, 2003

TECHNICAL DETAILS

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

1. Copies itself as:
   
   %Windir%Himem.exe
   %Windir%CommandEbdSex_Movie.Scr
   
   

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   Note: %Windir% is a variable. The worm locates the Windows installation folder (by default, this is C:Windows or C:Winnt) and copies itself to that location.

   ---

   
   
2. Copies itself to the root of all partitions as Sex_Movie.Scr.
   
   
3. Modifies shell line in System.ini file as the following:
   
   shell=Explorer.exe %Windir%Himem.exe
   
   
4. Creates a Script.ini file under any folder whose name is mirc. The worm uses this Script.ini file to send its copy Sex_Movie.Scr to other mIRC users who connect to the same channel.
   
   
5. Retrieves email addresses from files with the following extensions:
   
   • .htm
   • .html
   • .hta
   • .shtm
   • .shtml
   • .doc
   • .wps
   • .com
   • .exe
   • .lnk
   • .pif
   • .bmp
   • .swf
   • .scr
   • .wav
   • .mpg
   • .mp3
   • .mp4
     
     
6. Retrieves email addresses from the Outlook address Book.
   
   
7. Creates %System%Erifeci.Vxd, which stores the email addresses that the worm finds.
   
   
8. Uses Outlook, or the current MAPI program, to send itself to all the email addresses that it finds.
   
   The email has the following characteristics:
   
   
   Subject: %emailname%,How Are You?
   Message: %emailname%,How Are You?
   If You Like Cool Screen Save,Please Check This Attachment File.
   If You Have Other Cool Screen Save,Please Send To Me!My New E-Mail Address Is:New%emailname%@%emaildomain%.Thanks!
   Attachment: My-Cool-Screen-Save.Scr
   
   Subject: This Mail For My %emailname%!
   Message: I Very Like Play Computer Game,Attachment Is Very Well Computer Game.If You Like Play Too Me,Please Check This Attachment File.
   If You Have Other Game,Please Send To Me!My New E-Mail Address Is:New%emailname%@%emaildomain%.Thanks!
   Attachment: Well-Computer-Game.Exe
   
   Subject: %emailname%,Help Me!
   Message: Please Open Attachment File,You Can See A Photo,But I Dont Know Is Who?Please Help Me!
   Please Send Your Reply To Me! My New E-Mail Address Is:New%emailname%@%emaildomain%.Thanks!
   Attachment: Photo.Jpg.Scr
   
   Subject: Sex Movie For My %emailname%!
   Message: Attachment Is Sex Movie.If You Like,Please Check Attachment File.If You Have Other Sex Movie,Please
   Dont Forget Me,I Need!Please Send Your Movie To My New E-Mail Address:New%emailname%@%emaildomain%.Thanks!
   Attachment: Sex-Movie.Exe
   
   

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   Note: %emailname% is the user name in the email address. %domain% is the email domain. For example, if the email address is tester@domain.com, then %emailname% is tester, and %emaildomain% is domain.com.

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9. If the current day is not the 31st, the worm calculates a random IP address for a computer to infect. It attempts to authenticate itself to the IP addresses using the user names and passwords listed below. For each username, the worm will iterate through the passwords trying to make the connection.
   
   User names:
   • administrator
   • admin
   • master
   • webmaster
   • webroot
   • root
   • system
     
     Password:
   • internet
   • administrator
   • admin
   • master
   • network
   • webserver
   • server
   • root
   • webmaster
   • webroot
   • system
   • windows
   • computer
   • passwd
   • password
   • webroot
   • shell
   • login
   • webpage
   • nopasswd
   • nopassword
   • 1234
   • 4321
     
     
10. Copies itself as the following files to computers that it successfully connects to:
    
    • C:Sex_Movie.Scr
    • C:Windowsstartm~1programsstartupScanReg.Pif
    • C:winntstartm~1programsstartupScanReg.Pif

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.Erife@mm.
4. Remove the line that the worm added into the file system.ini.
5. Restore the Script.ini file from a clean backup.
   
   

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"

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.Erife@mm, click Delete.
4. Manually delete the file %System%Erifeci.Vxd, if it exists.

4. Editing the Win.ini file
If you are running Windows 95/98/Me, follow these steps:

1. The function you perform depends on your operating system:
   • Windows 95/98: Go to step b.
   • Windows Me: If you are running Windows Me, the Windows Me file-protection process may have made a backup copy of the System.ini file that you need to edit. If this backup copy exists, it will be in the C:WindowsRecent folder. Symantec recommends that you delete this file before continuing with the steps in this section. To do this:
     1. Start Windows Explorer.
     2. Browse to and select the C:WindowsRecent folder.
     3. In the right pane, select the System.ini file and delete it. The System.ini file will be regenerated when you save your changes to it in step f.
        
2. Click Start, and then click Run.
3. Type the following, and then click OK.
   
   edit c:windowssystem.ini
   
   (The MS-DOS Editor opens.)
   
   

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   Note: If Windows is installed in a different location, make the appropriate path substitution.

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4. In the [boot] section of the file, look for a line similar to:
   
   shell=Explorer.exe %Windir%Himem.exe
   
   
5. If this line exists, delete everything to the right of Explorer.exe.
   
   When you are done, it should look like:
   
   shell = Explorer.exe
   
   
6. Click File, and then click Save.
7. Click File, and then click Exit.

5. Restoring the Script.ini file from a clean backup
If the worm was able to delete Script.ini, you may have to restore this file.