W32.Entangle.Worm

SUMMARY

W32.Entangle.Worm is a mass-mailing worm that will send itself to all recipients in the Windows Address Book. It will also copy itself to the %system% directory.

NOTE: %System% is a variable. The worm locates the WindowsSystem folder (by default this is C:WindowsSystem or C:WinntSystem32), and then copies itself to that location.

W32.Entangle.Worm will create and run the Visual Basic script %Temp%send.vbs, which the worm will use to gather email addresses.

NOTE: %Temp% is a variable. The worm locates the default folder that Windows uses to store temporary files (by default this is C:WindowsTemp on Windows 95/98/Me and C:Documents and SettingsAdministratorLocal SettingsTemp on Windows NT/2000/XP), and then copies itself to that location.

Protection

• Virus Definitions (LiveUpdate™ Weekly) April 3, 2002
• Virus Definitions (Intelligent Updater) April 3, 2002

TECHNICAL DETAILS

The worm will copy itself to the %system% directory using one of the following file names:

• Kernel32.exe
• Win32DLL.exe
• WinFAT32.exe
• WinApi32.exe
• MpSrvr32.exe
• Msgsrv.exe
• Pstore32.exe
• Dfg32.exe

On Windows 95/98/Me computers, the worm also changes the shell line in the [boot] section of the System.ini from

shell = Explorer.exe

to:

shell = Explorer.exe <worm name listed above>

It will also create the file del.bat that will delete files created by the worm. Del.bat is not a malicious file.

It will create and run the Visual Basic script %Temp%send.vbs, which the worm will use to gather e-mail addresses. Upon execution the worm will display the following MessageBox:



The worm will send e-mail with the following characteristics:

Subject:

• Nice Tool
• Geschenk
• Joke!
• Wichtig!
• Einladung
• Cool
• Update
• Info
• Achtung!
• Gehard Schr÷der
• Papst
• Mitteilung
• Neuigkeit
• *G*

Body:

• FICKEN!
• Hi!
  Anbei das neue Desktop Tool 3.11!
• HAHAHA!
• Das MUSST du dir anschauen...
• Bills bester Freund *g*
• Neustes Outlook Update
• ....anbei die Wegbeschreibung
• Schau dir mal das Video an, es gibt gewisse Ähnlichkeiten mit Dir!
• Moorhuhn Version 3.11!
• Achtung neuer Virus gefunden!
• Ich hab Dir das neue Demo von *LPL* geschickt!
• Tolles Portrait!von unserem Gerhard!"&vbcrlf&"haha
• Jetzt wissen wir warum!
• Hallo,
  Achtung es kursiert ein sehr gefährlicher Virus! Ich habe dir schon mal den Virus-Check dafür an die Mail gehängt.
  Führ den Check bitte aus! Der Virus löscht nämlich dein komplettes Windows.
  Ciao bis dann!
• Endlich mal was wirkilch neues.

Attachment:

• Desk.exe
• Geschenk.exe
• Joke.txt.scr
• Outlockupt.exe
• Einladung.exe
• Cool.exe
• Moorhuhn.exe
• Info.rtf.scr
• Achtung.exe
• Politiker.bmp.scr
• Papst.exe
• VirFix.exe
• Neuigkeit.exe
• nude.exe
• Titten.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

To remove W32.Entangle.Worm, scan with NAV and delete files that are detected as W32.Entangle.Worm. If you are running Windows 95/98/Me, then remove the entry that the worm left in the System.ini file.

See the following detailed instructions.

To delete files that are detected as W32.Entangle.Worm:

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 whether 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 whether 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 W32.Entangle.Worm.

To edit System.ini:

NOTES:

• Follow the steps in this section only if you are running Windows 95/98/Me.
• For Windows Me users only: Due to the file-protection process in Windows Me, a backup copy of the file that you are about to edit exists in the C:WindowsRecent folder. Symantec recommends that you delete this file before you continue with the steps in this section. To do this using Windows Explorer, go to C:WindowsRecent, and in the right pane select the Win.ini file and delete it. It will be regenerated as a copy of the file that you are about to edit when you save your changes to that file.

1. Click Start, and then click Run.
2. Type the following:
   
   edit c:windowssystem.ini
   
   NOTE: If Windows is installed in a different location, then make the appropriate path substitution.
   
3. Click OK. The MS-DOS Editor opens.
   
4. In the [boot] section of the file, look for a line similar to the following:
   
   shell = explorer.exe <worm name from list in technical description>
   
   For example:
   shell = explorer.exe desk.exe
   
5. If the line exists, then select the entry after explorer.exe and then press Delete. When you have finished, only shell = explorer.exe should remain.
6. Click File, and then click Save.
7. Click File, and then click Exit.